Psychology Chapter 2

Lakukan tugas rumah & ujian kamu dengan baik sekarang menggunakan Quizwiz!

What does the word "Hawthorne" refer to?

A factory called Hawthorne Works Electric Company

survey

A method using questions to collect information on how people think or act. Surveys are prone to potential disadvantages that must be carefully considered. The questions asked in these surveys must be carefully worded to avoid biasing the outcome in either a positive or negative way (Borgers & Sikke 2004). ^This is known as wording effects.

Stratified random sample

A more careful approach to random sampling and is particularly useful when there are two or more identifiable subgroups in the population. A stratification divides the population first by subgroups, and then randomly takes samples in proportion to the population of interest. For example, in a sample class of 100 students with equal numbers of male and female students, our stratification would be to first separate students by gender and then select an equal number from each gender group. This process ensures equal numbers of males and females are represented in our sample.

According to this "The Magic of the Placebo" TED Talk, which type of placebo is best?

A needle is more effective than a capsule.

A Normal Distribution

A normal distribution is symmetrical but also has some important properties that allow for more detailed information about one's score, such as the percentile score. A standard normal distribution is based on a mean of zero and the standard deviation pf 1. There are properties that are known based on the number of standard deviations a score is above or below the mean.

correlation coefficient

A numerical representation of the strength of the relationship between variables (denoted as r). Positive and negative values convey the direction of a correlation, but these descriptions do not indicate how closely the two variables are related. The strength of a correlation is determined by a second metric, r. EX) The negative correlation between absenteeism and grades seemed to more closely resemble a straight line than, did the positive correlation between education and salary (more scattered). As a rough estimate, the closer the data points are to the line of best fit, the stronger the correlation is. Using a little math, we can numerically represent the strength of the relationship with a correlation coefficient...

assent

A person's affirmative permission to take part in a research study. In cases of decisional impairment, assent must be obtained in addition to informed consent.

participant observation

A research method in which a researcher becomes part of the group under investigation.

line of best fit

A straight line on a scatterplot showing the general relationship of data points. EX) Plot visualizes the relationship between grades and absenteeism. A line of best fit is drawn in red to represent the pattern between variables​.​ *(top left to bottom right) Note that as the rates of absenteeism increase, exam scores tend to decrease.​

sample

A subset (or portion) of a population.

replication

A term referring to a 'do-over' of a study using the same methods, but different subjects and investigators.

Correlation) Scatterplot

A type of graph that has one variable on the x-axis (the horizontal axis) and the other variable on the y-axis (the vertical axis) and provides a visual representation of relationships between variables. If the relationship is strong, the points on the graph cluster tightly together in a linear relationship (the word "linear" implies that the points would fall around a straight line). This relationship can not only be seen, it can also be described using a simple statistic called a correlation (denoted as r) to capture the direction and strength of a relationship between variables. One of the best ways to show directionality is with a scatterplot. Each data point on a scatterplot represents the intersection of scores on two variables (one on the x-axis and the other on the y-axis).

Simple random sample

A type of sampling where every individual in the population has an equal chance of participating. The advantage of a simple random sample is that, if large enough, it should approximate the larger population we wish to study.

E Vocab

1. ecological validity -- The extent to which research findings in the lab can be generalized to the real world. 2. eligibility criteria -- The combination of inclusion and exclusion criteria to create a set of characteristics shared by all participants that ensure that those participating will meaningfully help to address the research question. 3. entorhinal cortex -- A part of the cerebral cortex found on the ventral part of the temporal lobes and known to play a role in behavior and memory. episodic memory Memories whose contents pertain to specific events ("episodes"). 4. exclusion criteria -- An attribute of a person that would prevent them from participating research study.

I Vocab

1. illusory superiority -- The tendency to describe our own behavior as better than average. 2. inclusion criterion -- An attribute of participants that is necessary to be a part of a research study. 3. informed consent -- The process by which research participants learn about and understand the purpose, benefits, and potential risks of participating in a research study. 4. Institutional Review Board (IRB) -- A committee of independent people who review and assess whether a research project will be carried out in a way that is consistent with general ethical principles. 5. integrity -- An ethical principle that psychologists should engage in accurate, honest, and non-biased practices in the science, teaching, and practice of psychology.

three types of central tendency:

1. mean (the average score), 2. median (the middle score in an ordered set of data), 3. mode (the most frequently occurring number in a data set). Using a form of central tendency, such as the mean, allows a researcher to summarize large sets of data in an objective way. Although the mean is the most commonly used form of central tendency, it has one main disadvantage: It can be significantly affected by extreme values (known as outliers)

P Vocab

1. participant observation -- A research method in which a researcher becomes part of the group under investigation. 2. population -- All members of a group. 3. positive correlation -- When variables change in the same direction; as one variable increases, the other variable increases, or as one variable decreases, the other variable decreases. 4. procedural memories -- Memories whose contents pertain to how something is done, such as the motor skills involved in walking and riding a bicycle.

R Vocab

1. rationalism -- The belief or theory that reason is the key source of knowledge. 2. replication -- A term referring to a 'do-over' of a study using the same methods, but different subjects and investigators. 3. research ethics -- A set of principles or standards of behavior for psychologists to follow in research. 4. response bias -- The tendency for people to answer the question the way they feel they are expected to answer or in systematic ways that are otherwise inaccurate.

Ethics in Animal Research

Animal research answers questions we could never do with human research. There are very strict guidelines about how animals are to be housed and care for. There is also a focus on avoiding exposing them to unnecessary pain or suffering. Animals are used in approximately 7% of psychological studies. Most of the animal research is on white rats because their physiological response to environmental agents is similar to humans. Also, rats have a 2 year life cycle, which is substantially shorter than humans. Thus, researchers can view the entire life cycle of the rat in 2 years rather than 75 to 80 years in a human. Additionally, animals, like white rats, are first tested with new drugs to determine the effects on cancer and other diseases. The use of animal research has led to major advancements in medicine that has elongated the human life span.

Surveys Advantages/Disadvantages

ADVANTAGES OF SURVEYS: Data from large numbers of people. Relatively easy to administer. Study covert behaviors DISADVANTAGES OF SURVEYS: Have to ensure representative sample (or results not meaningful). People are not always accurate (courtesy bias). Susceptible to biases from both researchers and participants.

In a research survey, you have no particular opinion on the topic of discussion. Uncertain of how to respond, you tend to agree with most of the questions that the survey is asking. This is an example of:

Acquiescent response bias

Identify which of the following terms best corresponds to each of the descriptions.

Asking people who they will vote for in an election (survey) Observing that people who are more productive sleep less (correlation) Comparing the test scores of people who took a practice test to others who only reread the textbook (experiment) Job shadowing to better understand the stress of a workplace (participant observation)

Students attending a class are asked to listen to a lecture under three different levels of illumination while researchers record signs of attention. What is the dependent variable in this statement?

Attention

bias

An unfair or unequal representation of a person or thing.

Analogue Experiments

Analogue (analog) experiments are designed such that the conditions in the laboratory resemble real-life situations so that participants are induced to behave in ways that they would if their encountered the situation outside the laboratory.

Alfred Kinsey (1894-1956) revolutionized our understanding of people's sexual attitudes and behaviors by collecting surveys from more than 18,000 people.

Kinsey compiled the surveys into two publications known as the Kinsey reports: a.) Sexual Behavior in the Human Male (1948) b.) Sexual Behavior in the Human Female (1953). These publications provided a comprehensive and unprecedented insight into people's sexual attitudes, preferences, and orientation. Both publications highlighted the differences between social attitudes of sexuality and actual sexual practice. Both books quickly became best sellers, and Kinsey's contributions helped spark a massive cultural and social upheaval: the sexual revolution of the 1960s.

A researcher randomly assigned factory workers to work in either a brightly-lit, moderately-lit, or dimly-lit factory floor and measured their productivity (in units produced per day). What is the independent variable in this statement?

Lighting level at the factory floor (bright, moderate, or dim lighting)

Natural Experiment or Field Study

Natural experiments (also referred to as field studies) are used to examine the psychological effects of some unpredictable or unusual event, such as a hurricane, a plane crash, a tornado, a school shooting, etc. Participants are selected for inclusion in the study by virtue of having been a survivor or bystander in the event. Since participants are not randomly assigned to a group, it is not a true experiment, rather it is a research study that is done in the field. Researchers may seek to understand the effects of these events on peoples' lives, their emotional adjustment following a tragedy, or their resilience.

Observation of behavior in real world settings is best described as ______________ observation.

Naturalistic The place in which participants typically are and how they usually behave is their natural environment. Because they're being observed by an experimenter, we call this naturalistic observation.

All members that belong to a group are called a ______________.

Population

Damon Brown's work found that the change in the working environment was not the important factor on productivity. Rather, it was simply that the employees were being observed. Which step in the scientific method does this address?

Data analysis

When a study is over, participants are given further details about the purpose of the experiment, their role in helping to answer the research question, and are also informed if deception was used in the experiment. This part of the study is called ___________.

Debriefing

Central Tendency

Descriptive statistics are a collection of ways to describe the data in the simplest way possible, which involves the use of quantitative values. You are likely already familiar with ways to represent data using descriptive statistics. For instance, if we were to ask you for one piece of information that defines your undergraduate performance, what would you say? Most students will likely say grade point average (or GPA). The average, also known as the mean, is a relevant and frequently used measure of the central tendency of the data. In any data set, the central tendency is the score that best represents the others.

Conducting the experiment - which involves...

Designing and running the experiment - is how we test our hypothesis. Here, we analyze the data and make a decision about how our data compare to our expectation, and this happens after we test our hypothesis.

The American Psychological Association (APA) has developed a series of FIVE ETHICAL PRINCIPLES to help psychologists develop their research practice:

Principle A: Beneficence and Non-maleficence Principle B: Fidelity and Responsibility Principle C: Integrity Principle D: Justice Principle E: Respect for People's Rights and Dignity

A researcher randomly assigned factory workers to work in either a brightly-lit, moderately-lit, or dimly-lit factory floor and measured their productivity (in units produced per day). What is the dependent variable in this statement?

Productivity (units produced per day)

The goal of a descriptive study is to:

Gather data about a given subject

If Jamal is participating in a research study, what event(s) should have already taken place?

IRB review Informed consent

Order the following steps of research ethics from the first thing that happens to the last.

IRB review participant recruitment informed consent study participation debriefing

Samuel was administered the Weschler Intelligence test and got a score of 115. Knowing that the mean is 100 and the SD is 15, what is Samuel's percentile (basically, how many people have scores lower than Samuel)? If you think this through, you already have all the tools to solve this problem. Remember the standard normal curve

If Samuel's score is 115, then his Z-score is 115-100/15 = 1.0 His score is one SD above the mean. How many scores fall between the mean and +1 SD? Hopefully, you see that 34% of scores fall between mean and +1. What other critical piece of information do you need? He clearly is not in the 34th percentile, but rather the 84th percentile. This was determined by adding the number of scores below the mean (50%) + 34% = 84%.

An experiment is used to directly link ideas within a cause-and-effect relationship. In its simplest form, predicting cause-and-effect (HYPOTHESES) relationships can be framed in the following way:

If _[I do this]_, then _[this]_ will happen. From the above statement, you can see that we are making a prediction about the outcome of an event because of something that we are doing. Formally, we call this prediction a hypothesis.

A correlation coefficient equal to +1.00 between scores on a written driver's license test and performance on a practical driving test means that:

Increased written test performance is associated with increased performance on a practical test

You perform an experiment and carefully ensure that only the independent variable caused changes to the dependent variable. In this case, our experiment has a high level of

Internal validity.

J L M N Vocab

J1. justice -- An ethical principle in research whereby those people who participate in the research process should also be the same people who stand to benefit from the research outcomes. L1. line of best fit -- A straight line on a scatterplot showing the general relationship of data points. M1. maleficence -- The act of doing harm. N1. naturalistic observation -- Observation of behavior as it happens, without an attempt to manipulate or control the subjects' natural environment. N2. negative correlation -- Variables that change in the opposite direction. An increase in one variable leads to a decrease in the other.

Conclusion ) reliability

The higher the reliability of a test the better. Reliability should be .70 or higher (.85 for internal consistency) Reliability can be affected by many factors If a test is not reliable, it is useless

Experiments are different from other forms of research because:

The independent variable must be manipulated.

wording effects

The influence of language, or wording, on people's responses to survey questions.

Standard deviation measures are:

The spread of data around the mean

Why are control groups important in experiments?

To allow for a comparison with the experimental group

Psychometric Properties of Tests and Measures

To better understand the quality of a measurement instrument, there are aspects of that measure to consider, which are the psychometric properties of the measure. Any test, measure, or questionnaire should have good psychometric properties: this includes the measure's reliability and validity. Before we can cover reliability and validity in detail, we must first revisit the correlation coefficient.

What is one major purpose of correlational research?

To identify relationships between two variables There is no independent variable manipulation in correlation research; it's typically naturalistic observation or other descriptive study. We only get a sense of the (positive, negative, or zero) correlation between two variables.

When is a case study the most useful?

When a participant has a rare condition. We conduct a case study when we're investigating a rare or unique phenomenon or condition and we need in-depth information on the person involved. There aren't other people like HM who have had their hippocampal lobes removed and the resulting memory deficits.

In which part of the scientific method does a scientist propose a problem to solve?

When asking a question

(T/F?) The term "Hawthorne effect" refers to the effect the presence of an observer can have on the behavior on the subjects or a temporary change in behavior due to the novelty of the situation...

TRUE Participants only react to new people who might be observing their behavior, and the effects go away after they get used to the presence of this new person; participants' behavior will return to its typical pattern.

Internal consistency Reliability (IC)- Split-Half method:

Test items are divided into two equal parts. Scores from the two parts are correlated with each other to get a measure of internal reliability. A common way of doing the split-half method is for items to be separated into odd and even items. Odd items (1, 3, 5, 7, 9, etc.) are correlated with Even items (2, 4, 6, 8, 10, etc.). The correlation between these different halves of the test is one form of IC reliability

Psychologists use statistical analysis to ______________.

Test whether the data from an experiment reject or fail to reject their hypothesis

correlation and correlation coefficient

correlation - A measure (denoted as r) that captures the direction and strength of a relationship between variables. correlation coefficient -A numerical representation of the strength of the relationship between variables (denoted as r).

The idea of random assignment is the notion that

each participant has an equal chance of being assigned to either one of the independent variable conditions (in this case it is to either play a violent v9==. The researcher would also have to define how aggression would be measured. The researcher may base their measurement of aggression of methods or measures previously used in the literature.

A control group represents a researcher's efforts to remove or control the influence of any extraneous variables that might have an effect on a dependent variable. The goal here is to be assured that the only differences between our groups are those related to the independent variable. We want to avoid any systematic difference in attitudes or abilities that might bias our results By controlling for factors that might bias the outcome of an experiment, we are addressing... internal validity:

the degree to which results may be attributable to the independent variable rather than some other effect of our experiment. Basically, was the experiment done "right"? If we control for internal threats to validity, we should be able to repeat the experiment again and again and come to the same conclusion.

D vocab

1. data -- Facts or information collected, examined, and considered for decision-making processes. debriefing Information provided to participants about what the researcher was investigating and how their participation will contribute to the research question. 2. deception -- The act of withholding information about the purpose and procedures of the study during the informed consent process. 3. decisional impairment -- Instances that diminish a potential participant's capacity to provide informed consent. 4. descriptive methods -- Any means to capture, record, or otherwise, describe a group. These methods are concerned with identifying 'what is' rather than 'why it is.'

What is the best definition of a hypothesis?

"The predicted outcome of an experiment or research study." A hypothesis is an educated prediction about the potential outcome of a study. We make a hypothesis before we conduct an experiment about what will happen, which means that a hypothesis can't serve as an explanation for anything that has already happened.

The Milgram Obedience study has received considerable criticism for lack of consideration of which ethical principles?

1. Beneficence and Non-maleficence 2. Respect for People's Rights and Dignity Participants didn't know that they would be administering shocks to a learner, and an authority figure kept telling participants to keep going even when they seemed distressed (deception and therefore a disrespect for rights and dignity). The reason for doing that, of course, was to simulate on a much smaller and milder scale what the SS guards were doing and to potentially see how regular people could commit atrocious acts against others. Participants also thought they had just killed a person - when they administered the XXX level of shock for incorrect answers, which violates (beneficence and non-maleficence). They weren't directed to counseling services if they felt distress even after it was explained that the learner did not receive shocks.

Overview of Common Methods of Assessing Validity:

1. Content Validity: items on a measure cover a representative sample of the construct being measured 2. Criterion-related Validity 1. Concurrent validity: measure correlates with an outcome (criterion) 2. Predictive validity: measure forecasts some future outcome *^*^Criterion-related validity refers to the extent to which a test score is related to some other measure called a criterion. Criterion-related validity can be established using one of the following research designs: (1) Concurrent Validity and (2) Predictive Validity. 3. Construct Validity: construct being measured correlates significantly with similar constructs (convergent validity) and does not correlate with unrelated constructs (divergent validity) *^*^Construct validity assesses the extent to which a test actually measures the construct that it is supposed to measure.

Hypotheses, 5 characteristics: Consistent, Simple, Specific, Testable, Falsifiable.

1. It should be consistent with prior observations or an existing theory. A hypothesis is not simply a "shot in the dark" (wild guess). Rather, a hypothesis should be an educated prediction based on what you have already learned from descriptive methods (such as observations, case studies, or surveys) that provide an understanding of "what is." A hypothesis builds upon those observations to address "why it is." 2. It should be as simple as possible. The goal in an experiment is to identify a cause-and-effect relationship between two variables. Adding more than two variables complicates the relationship. As such, answering complex research questions may require multiple experiments, each with its own simple hypothesis. 3. It should be specific. A good hypothesis provides all the details about who we are measuring, what changes will be made during the experiment, and what effect we predict those changes will have on the outcome of the experiment. 4. It should be testable. A specific hypothesis states what evidence will be measured and used as a point of comparison. 5. The hypothesis should be falsifiable. Are there clear conditions or outcomes that could prove your hypothesis false? At first glance, you may be wondering why falsifiability is a necessary component of a hypothesis. After all, if we have a theory, why would we create an experiment that might not work? If you're scratching your head, consider what would happen if all predictions were only found to be true; inevitably, two theories will contradict one another EX) "the world is flat" versus "the world is round". If we can't falsify either of these theories in experiments, we would never be able to distinguish fact from fiction.

With Vulnerable Populations, the researcher must construct experiments with additional safeguards in place to ensure the protection of vulnerable populations during the research process. Specifically, researchers should consider the following:

1. No study should ever be conducted on vulnerable populations if the research question could be reasonably carried out using participants without these vulnerabilities. 2. When research is carried out with vulnerable populations, researchers should be responsive to the needs, conditions, and priorities of these individuals. IRB committees should include members with expertise on these populations. 3. In instances of decisional impairment, consent to participate in the research process requires that two types of consent are acquired: Parents and guardians must provide informed consent on behalf of the participant and the participant must provide assent (affirmative permission to take part in the study). In this case, both parties are needed to give the okay to participate before their participation can begin. 4. In cases of situational vulnerability, additional safeguards should be put in place to prevent exploitation. For instance, a study may include an impartial third party to advocate on behalf of individuals who might not otherwise feel comfortable doing so.

Blind Design Concepts

1. Placebo effect - the phenomenon in which the expectations of the participants in a study can influence their behavior. 2. Single-blind study- subjects do not know if they are in the experimental or the control group (reduces placebo effect). 3. Experimenter effect - tendency of the experimenter's expectations for a study to unintentionally influence the results of the study. 4. Double-blind study- neither the experimenter nor the subjects knows if the subjects are in the experimental or control group (reduces placebo effect and experimenter effect).

Sample Selection

1. Simple random sample 2. Stratified random sample 3. Non-random sample When planning an experiment, researchers will need to select experimental and control groups. Remember from our section on surveys that the goal of any selection process is to create groups that are fair (i.e., we are not biasing one group over another) and representative of the bigger population. By creating fair groups, we can be confident that any difference we see between groups in our experiment is caused by the independent variable. In this section we discuss some common sampling techniques researchers use to build research groups

To approve the use of Deception in research, IRBs must meet four criteria:

1. The research poses no more than a minimal risk to participants. This means that the research is unlikely to cause emotional or physical discomfort to participants. 2. The deception does not affect the well-being and the rights of the participants throughout the study. 3. Researchers must provide justification that using deception is the only way to conduct the study. There should be no other reasonable alternative approach to addressing the research questions. 4. After the participant's role in the study is finished, participants should be debriefed by researchers and provided with information about what the researcher was investigating and how their participation will contribute to the research question. On the rare occasions when deception is used in a study, participants must be told about the deception and given reasons why this was necessary to answer the research question. Participants should also be allowed to ask questions and seek clarification about any part of the study. The goal of this process is not only to provide information to participants, but also to help them leave the study in a similar mental state as to when they entered the study.

S Vocab

1. sample -- A subset (or portion) of a population. sampling error A sample that deviates from a true representation of a population. 2. scatterplot -- A type of graph that has one variable on the x-axis (the horizontal axis) and the other variable on the y-axis (the vertical axis) and provides a visual representation of relationships between variables. 3. scientific method -- A six-step method of acquiring knowledge and methodologically answering questions. 4. scientific theories -- Rational explanations to describe and predict future behavior. 5. semantic memories -- Memories whose contents relate to specific facts and pieces of meaningful information not based on personal experience. 6. situational vulnerability -- When the freedom of 'choice' to participate in research is compromised as a result of undue influence from another source. 7. socially desirable bias -- Participants respond to questions in ways that would be seen as acceptable by others. 8. survey -- A method using questions to collect information on how people think or act.

It has been determined that approximately 1.6 standard deviations away from the mean represent the most extreme ___% of a population on one side of the distribution:

5

Direction of Correlations) ZERO

A Zero correlation indicates that there is no apparent relationship between variables. When the correlation is zero, it means that the variables are unrelated and the data points on a scatterplot would appear random. For example, there is no correlation between vaccination early in life and the development of autism.

volunteer bias

A bias whereby only a motivated fraction of a population respond to a survey or participate in research. EX) Alfred Kinsey: Sexual Behavior in the Human Male (1948), Sexual Behavior in the Human Female (1953) Statisticians who evaluated Kinsey's methods felt that his findings may have been subject to a key survey-related bias: who was willing to participate in this survey, and were those who did representative of the rest of the population? Among the conservative sexual attitudes of the 1950s, many Americans were reluctant to discuss their sex lives publicly. The assumption was that people that do volunteer to be interviewed about taboo subjects like sex may not be representative of the rest of the population. Small few who were willing and ready to talk about their sex lives were likely overrepresented in the survey (Strassberg & Lowe, 1995). Aspects of the survey also required adult respondents to think back over several years, even decades, about early sexual experiences. However, despite the caution of surveys presented here, the power of surveys to inform and shape our perspectives is clear.

Institutional Review Board (IRB)

A committee of independent people who review and assess whether a research project will be carried out in a way that is consistent with general ethical principles. Ensuring the following: 1. The proposed study will use sound research design. 2. Risks associated with participation in the study are minimized and reasonable. 3. The benefits of the research outweigh any potential risks. 4. All participants can make an informed decision to participate in the study, and that decision may be withdrawn at any time without consequence to the participant. 5. Safeguards are in place to protect the well-being of participants. 6. All data collected will be kept private and confidential.

Variability

A difference in the measure of the spread of data You would be correct to say that although the means are the same, the data sets are quite different. The difference between these groups is in their variability. Group A scores varied from the mean with a range of 40 points (100 - 60 = 40); however, the scores of Group B have less variability and are tightly packed around the mean with a range of 4. The mean only provides a partial description of a data set, and the variability helps to fill in otherwise missing details about a data set. Although the range is one measure of variability, it is not a robust measure. The most commonly used measure of variability is the standard deviation (SD). The average of the squared deviation scores is called the variance

With observational approaches and correlations, we can describe events and behavior and help formulate HYPOTHESES. Experimental research allows us to understand how separate pieces of facts and information are related...

A hypothesis is a prediction about what will happen in research. The aim of conducting experimental research is to explain cause-and-effect relationships. Using the scientific method, we can find support for or modify an existing theory, as well as accumulate evidence through replication to develop new theories.

Correlation

A measure (denoted as 'r') that captures the direction and strength of a relationship between variables.

ablation

A medical procedure to remove or otherwise destroy tissue.

Examples with the type of descriptive method being used...

A researcher polled students to ask where they were spending spring break. =(Survey) To better understand the effectiveness of a professor‚ the department chair sat in on a class and asked students about their experiences with the teacher. =(Participant Observation) A biologist traveled to the Tanzanian Forest to study the social and family interactions of the wild chimpanzee. =(Naturalistic Observation) In survey research, participants only have to answer questions or make ratings and aren't observed for longer periods of time. In naturalistic observation, experimenters observe participants and record their behavior when the participants are in their typical or natural environment. In participant observation research, the experimenter tries to blend in with their participants and collect detailed information about participant behavior.

sampling error

A sample that deviates from a true representation of a population.

research ethics

A set of principles or standards of behavior for psychologists to follow in research.

scientific method

A six-step method of acquiring knowledge and methodologically answering questions. 1. Identify the problem 2. Gather information 3. Generate a hypothesis 4. Design and conduct experiments 5. Analyze data and formulate conclusions 6. Restart the process

population

All members of a group.

In summary, naturalistic observation, participant observation, and case studies allow researchers to study small groups (or even individuals) to produce rich descriptive data of behavior.

Although a powerful perspective, we are likely not capturing a representation of an entire population of people. As such, researchers often turn to surveys to describe larger patterns of behavior.

hypothesis

An educated prediction about the outcome of an experiment.

justice

An ethical principle in research whereby those people who participate in the research process should also be the same people who stand to benefit from the research outcomes.

The Experimental Method:

An experiment is a research procedure in which one (or more) variables are manipulated and the effect of that manipulation is subsequently observed (and measured) on another variable. For simplicity, let's consider a scientific experiment (a research process) in which one variable is manipulated (changed in some way), and the effect of this manipulation on another variable is observed and/or measured. The variable that is manipulated is the independent variable, while the outcome variable that is being observed or measured is the dependent variable. Experiment - a deliberate manipulation of a variable to see if corresponding changes in behavior result, allowing the determination of cause-and-effect relationships. Operational definition - definition of a variable of interest that allows it to be directly measured. Independent variable (IV) - variable in an experiment that is manipulated by the experimenter. Dependent variable (DV) - variable in an experiment that represents the measurable response or behavior of the subjects in the experiment (the outcome measure). Participants would have to consent to participate in the experiment and sign an informed consent form that lays out all aspects of the research, including any risks or benefits. The researcher decides that she will compare the two groups after one month of mindful meditation or just listening to music. To measure level of depression, the researcher selects an existing measure, the Beck Depression Inventory II, which has demonstrated reliability and validity. The researcher decides to use a sample of 60 participants and randomly assigns 30 participants to the meditation condition and half the music condition. The mindful meditation condition can also be referred to as the experimental group and the music condition is the control group (comparison group). The experimenter chose listening to music during the same span of time because it is not known to effect depression level. Experimental group - subjects in an experiment who are subjected to the independent variable treatment. Control group - subjects in an experiment who are not subjected to the independent variable and who may receive a placebo treatment (controls for confounding variables).

field experiments

An experiment that takes place in 'real-world' settings in which a researcher manipulates and controls the conditions of the behavior under observation.

case study

An in-depth analysis of a unique circumstance or individual

Vulnerable Populations (Special Ethical Considerations)

Any group of individuals who may not be able to provide free and informed consent to participate in research. 1. Decisional impairment: Instances that diminish a potential participant's capacity to provide informed consent. EX) A potential participant has diminished capacity to provide informed consent. Typical examples include children and the mentally disabled, who may not be able to understand their rights as participants or the risks associated with their participation. 2. Situational vulnerability: When the freedom of 'choice' to participate in research is compromised as a result of undue influence from another source. EX) Freedom of "choice" to participate in research is compromised as a result of undue influence from another source. Common examples include military personnel and prisoners who may feel coerced or obligated to participate in research out of fear of being punished if they do not. OR people in economically disadvantaged situations who may be inclined to participate with the expectation of benefits, like money or medical care, that would not be provided if they do not agree to participate.

descriptive methods

Any means to capture, record, or otherwise, describe a group. These methods are concerned with identifying 'what is' rather than 'why it is.'

Extraneous variables (also known as confounding variables)

Any variables that are not the focus of study, but that may influence the outcome of research if not controlled. For example, when manipulating violent video game playing, it is important that gender is spread evenly across the violent and non-violent gaming conditions. Quite simply, males tend to be more physically aggressive than females (Hyde, 2005), so we expect males to be more physically aggressive regardless of the type of video game they play. If we unequally distribute males and females between groups, we would be introducing an extraneous factor that could affect our measurement of aggressive behavior. One solution might be to equally distribute males and females between the groups to ensure there is no gender bias. By controlling as many extraneous variables as possible, we can be confident that changes we observe in the dependent variable (aggressive behavior) are caused by the effects of our independent variable (the type of video game played).

In clinical neuroscience, Henry Molaison—usually referred to as "H.M." in the scientific literature—is an excellent example of how a case study can be used to gain insight into behavior

As a young boy, Henry started to experience mild seizures after falling off his bike and hitting his head. His seizures became progressively worse as he aged. By the time Henry reached his late 20s, he could no longer live a normal life because of the frequency and severity of his seizure attacks. On the advice of his neurosurgeon, his last resort was bilateral ablation (surgical damage) to his ventral medial temporal lobes (which includes the hippocampus and the entorhinal cortex), as this brain tissue was believed to be the point of origin of Henry's seizures The surgery did effectively treat Henry's seizures; however, there was an unforeseen, disturbing side effect. It seemed that he could no longer form new memories. In the decades that followed, H.M. would become the most studied person in the history of psychology (Squire, 2009). While the details of his case are unique, this was an opportunity for researchers to explore the role of the hippocampus in the formation of memory (Penfield & Milner, 1958), which ultimately led to the identification of different types of memories, like episodic, semantic, and procedural memories

Correlations

As previously stated, correlations assess the linear relationship between two variables. You also need to understand what is considered a variable; again, by looking at the beginning of the word, a variable is expected to vary. A variable is any event or behavior that can assume two or more values.

A study found a correlation coefficient of .85 between spatial navigation skills and scores on a driving test. What would this suggest?

As spatial navigation scores increase, so do scores on a driving test. A positive correlation means the values of both variables change together. As one increases, so does the other. As one decreases, so does the other.

The Tuskegee researchers violated this ethical principle when they failed to provide medical treatment to participants:

Beneficence and Nonmaleficence

Ethical principles, with appropriate corresponding statements:

Beneficence and Nonmaleficence-- "Protection of the research participant is more important than the pursuit of new knowledge..." Fidelity and Responsibility-- "A researcher's obligation to say something when they believe that participants are not being treated fairly..." Integrity-- "A researcher makes every effort to remove factual errors from the study report..." Justice-- "Researchers should not exclude any group from participation for reasons that are unrelated to the study..." Respect for People's Rights and Dignity-- "The capacity and rights of all individuals to make their own decisions..."

Which of the following questions would address the internal validity of an experiment?

Can changes in the DV be explained only by manipulation of the IV?

non-random sample

Can take many forms but generally follows the rule that not all individuals are equally likely to participate. For instance, if a researcher wants to study the effects of concussions in sports on mental health, it would not be ethically possible to randomly assign athletes to a concussion or non-concussion group. In this case, they would have to recruit athletes with pre-existing conditions who are available to participate in the research. In this case, the researchers might decide to create a convenience sample—a group of individuals that are only selected because of a pre-existing condition, convenience, or easy access to participation.

Henry Molaison (HM)- From case study of the Man with No Memory

Case studies yield data that is rich in detail and of greater depth than other methods. The case study method is often used with rare cases (or rare disorders) in which large numbers of participants would not be available. They can assist researchers in adapting ideas and developing novel or creative hypotheses which can be used for later evaluation. The hyperlink below brings you to a brief article about 5 famous case studies in psychology.

Experimental research is the only type of research that enables researchers to make conclusions about:

Cause and effect

Validity of measures recap vocab

Correlation coefficients (r) measure the relationship between two variables and differ in strength and direction (+/-) Reliability is the consistency of a measure; consistency over time, between forms, within the measure itself, and between raters Validity: is the accuracy and use of a measure; validity can be assessed by its content, using criterion-related validity that includes concurrent validity and predictive validity, and construct validity (by showing convergent and divergent validity).

Direction of Correlation definition

Correlations can have positive, negative, or zero directionality. It is important to understand that positive directionality does not imply inherent "goodness," and negative directionality does not denote "badness."

Imagine that we are interested in how maternal separation affects stress early in life. To explore this relationship, we separate young rat pups from their mothers for 15 minutes per day and measure corticosterone levels (a hormonal marker of stress) just before returning the pups back to their mother. What is the DEPENDENT variable?

Corticosterone levels A dependent variable is what an experimenter measures to see if there is a change in behavior (usually) due to some treatment. The treatment (or independent variable) is that rat pups are separated from their mother. The dependent variable is maternal stress, and the measure of corticosterone levels will reflect any changes due to the mother's stress.

In psychology research, Internal Review Boards do which of the following? (Select all that apply)

Ensure that sound research methods are used during the study Evaluate the potential risks and benefits of participation Ensure that all participants will be provided with enough information to make an informed decision to participate.

Chapter 2, Recap Pt. 3

Experiments are conducted to determine whether manipulating an independent variable causes changes in a measured dependent variable. Independent variables are manipulated by researchers (resulting in "experimental" and "control" groups), while changes in a dependent variable or "outcome measure" represent the effect of the researchers' manipulation. Placebo effects can occur if a person believes in a cause-and-effect relationship; these effects represent the power of participants' expectations in an experimental setting and can be mitigated by the use of placebo groups. Internal validity exists in an experiment when a cause-and-effect relationship can be established; extraneous (confounding) variables threaten our ability to claim that an independent variable causes a change in a dependent variable. External validity describes the extent to which the results of an experiment are generalizable to other people, other settings, other time periods, or other contexts. Descriptive statistics are used when we want to report on our results descriptively: Measures of central tendency (e.g., mean, median, and mode) attempt to find a number that best represents the data, while measures of variability (e.g., standard deviation and variance) help describe the distribution or "spread" of the data. The mean is the average score in a data sample, the median is the "middle" score if the scores were rank-ordered from lowest to highest, and the mode is the most common score. Standard deviation describes the average distance from the mean score in a data set; this helps us understand whether scores are all very close to the mean or more spread out. Inferential statistics allow us to make inferences about whether differences exist between two (or more) sets of data; for example, whether or not a true difference is likely to exist between experimental and control groups. Such differences could be statistically significant depending on the results of the analyses used on the data.

A researcher is conducting an experiment to test if meditation helps improve focus and attention in class. During one of the meditation sessions, the fire alarm disrupts the amount of time some students have to meditate. In this example, the fire alarm is what type of variable?

Extraneous variable.

F and H Vocab

F1. fidelity -- The ethical principle of developing trusting relationships between researchers and participants. F2. field experiments -- An experiment that takes place in 'real-world' settings in which a researcher manipulates and controls the conditions of the behavior under observation. H1. hippocampus -- A part of the cerebral cortex known to play a role in the transference of certain types of memories into long-term memory stores. H2. hypothesis -- An educated prediction about the outcome of an experiment.

(T/F?) The primary strength of survey research is the ability to determine cause-effect explanations.

FALSE The primary strength of a true experiment in which an independent variable is manipulated (has at least two conditions) is that we can determine cause-and-effect explanations. Surveys give us correlations at best. We have to take that a step further with an experiment to have a directional explanation.

A major purpose of all surveys is to predict future performance.

False

Practice Exercise: The Case of Farmer Joe

Farmer Joe is having problems with his squash. He feels that they are not nearly as big as they should be. He has bought 2 types of fertilizer, which he thinks will improve the size of his squash. Fertilizer A - which costs $10 a bag - claims to increase the size of the squash by 50%. Fertilizer B - which also cost $10 a bag - claims to improve the size of the squash, but doesn't say by how much. Being a smart farmer, Farmer Joe has hired you to tell him what he should do. How would you determine which fertilizer to use?

Indicate how each of the following is correlated (positive, negative, or zero):

Height and weight (POSITIVE) Height and shoe size (POSITIVE) Attractiveness and popularity (POSITIVE) Absenteeism and grades (NEGATIVE) Facial blemishes and self-esteem (NEGATIVE) Shoe size and intelligence (ZERO) Student ID number and intelligence (ZERO)

If the number of "hours spent studying" is positively correlated with the "test score," what can be concluded?

Higher exam scores are associated with a greater number of hours spent studying. We don't know if the variables are perfectly correlated with -1.0 or +1.0 in a straight line. We don't know about any other variables that influence the values of these two variables. We also can't say that studying more causes (will result in) better grades. All we know is that the two variables are positively correlated.

An Applied Experiment

Imagine you hear of a new brand of toothpaste, Zazzy White, which claims to whiten your teeth better than any other toothpaste available. You are skeptical of these unproven claims (as you should be), and so you decide to conduct an experiment. Since you are interested in determining whether Zazzy White differs from other toothpastes, you select a number of different tooth pastes to compare it to: Colgate Total with Whitening; Crest Whitening; the generic brand of whitening toothpaste (and any other brand you want to test). Your hypotheses [predictions about the outcome of the experiment; hypothesis = singular] are based on your expected outcome and are as follows:Hypothesis 1: It is hypothesized that Colgate Total with whitening will whiten teeth better than the other brands tested. Hypothesis 2: It is hypothesized that Zazzy White will not differ from Crest Whitening or the generic brand of whitening toothpaste in the participants change in tooth whitening. Zazzy White, Crest whitening, and the generic whitening toothpaste are expected to perform similarly with regard to tooth whitening, with no differences between these brands.

Survey Research: Correlational Research

In survey research, you administer surveys to gather a lot of information about different variables. Using surveys, researchers will ask a series of questions about the topic under study. Questions are designed to extract specific information from a group of people. The use of surveys is an effective approach to gather a lot of information/data. The use of surveys is correlational research. It looks for the relationship between variables expressed as a correlation coefficient (r) Surveys should be administered to a representative sample. One way to ensure that it is a representative sample, meaning the sample represents the population of people it is supposed to represent, is to use random selection. With random selection, each participant is randomly selected and has an equal change of being chosen to be part of the research sample. The sample is a subset of the larger population of persons of interest. A population are defined as the entire group of people or animals in which the researcher is interested. The population depends on the research purpose - if the researcher is about children with autism, then the population is children with autism. A random sample is when everyone in the population has an equal chance of being selected; this is often not feasible as researchers often do not have access to everyone within the population of interest. Although surveys can be sent to persons in distant locations, the return rate of the survey is critical to the validity of the research. The return rate is the percentage of surveys returned in comparison to the total number distributed. Low return rates brings into question the representativeness of the sample and possible differences between the persons who returned the survey and those who did not (which cannot be assessed). Low return rates affect the validity of the research.

Which of the following numbers appears in the middle of a data set?

Median

procedural memories

Memories whose contents pertain to how something is done, such as the motor skills involved in walking and riding a bicycle.

An employer completes a survey on how they agree or disagree with social equality in the workplace. Not wanting his employer to think that he is sexist, the employee decides to answer "agree" to all questions. This is an example of:

Social desirability bias

Naturalistic Observation:

Naturalistic observation involves watching animals or humans behave in their normal environment. The researcher makes observations of behaviors without attempt to manipulate or control conditions. This is most likely representative of human's or animal's true behavior in real world setting. Since there is no control over your subjects behavior, it is difficult to determine exact cause of behavior. Jane Goodall was famous for her decades of naturalistic observation done on chimpanzees in their natural habitat in Africa. She initially sat far from the group she was observing. Over time, they actually got closer to her and would interact with her. Although she was simply watching the chimpanzees, clearly her presence was noted and eventually she was accepted into their group. She eventually was able to interact with them; she treated them as individuals and even named them. Major Advantage of naturalistic observation: Realistic picture of behavior Disadvantages of naturalistic observation: Observer effect

Descriptive statistics describe the data (scores).

Note: Data is plural; datum is singular Central Tendency: Methods of describing a summary score that represents how participants scored Mean - arithmetic average (sum of scores/total # of scores Median - Middle score; 50% of score above and below Mode - Most common score What is the Median? (50th percentile score) 2. What is the Mode? (most popular score) 3. What is the range? (highest - lowest score)

naturalistic observation

Observation of behavior as it happens, without an attempt to manipulate or control the subjects' natural environment.

Protecting Human Participants:

Of utmost importance and concern when conducting psychological research studies is the protection of the rights, needs, and safety of participants. Every institution such as a university, medical school, private research facility, mental health center, or teaching hospital has an Institutional Review Board (IRB) which carefully reviews research proposals and monitors every study that is being conducted at that institution to ensure that the safety and rights of participants will be protected. Included in the rights of research participants are the following provisions: 1. participation in the research study is voluntary and may be discontinued at any time 2. participants must be adequately advised about what the study entails (the possible benefits and risks), and must sign an informed consent form 3. the benefits (or information to potentially be gained from the study) must outweigh the risks of the research 4. the participants must be protected from psychological or physical harm 5. after analysis is completed, the participants can have access to information regarding the study 6. the privacy of the participants is protected through the ethical principles of confidentiality and anonymity

Phineas Gage- case study

One case study that was critical in establishing the role of the frontal lobe of the brain was that of Phineas Gage. Phineas Gage was a foreman who worked on the transcontinental railroad in the mid 1880's. One day when explosive were being used to clear an area, a long cylindrical rod was blasted through Phineas' head, entering below his left eye and leaving at the top of his head near the front where the frontal lobes are located. Prior to the accident, Phineas was easy-going and had no problems making decisions or getting along with others. From the deficits seen in Phineas Gage after the accident, it was clear that the frontal lobe of the brain was crucial in executive functions, impulse control, and aspects of personality. Below is a figure depicting the path of the iron rod that blasted through Phineas' head. There is also a picture of Phineas Gage holding the iron rod that passed through his head.

Review of SD

TO CALCULATE A STANDARD DEVIATION (THINK OF WHAT YOU ARE DOING AND YOU WILL NEVER NEED A FORMULA Calculating a SD Determine the mean of the scores Calculate the difference score between the score and the mean (subtraction) Square the difference score; (Score - Mean)2 Sum the squared deviation scores Divide by n-1 in a sample; this is the variance SD = the square-root of the variance

confounding variable

Other variables that may influence one or both variables that we are measuring, thereby influencing the correlation coefficient. The correlation between ice cream sales and homicides illustrates the importance of understanding the potential effect of a confounding variable—that is, another variable that may influence one or both variables that we are measuring, thereby influencing the correlation coefficient Although ice cream consumption and homicide rates are positively correlated, the relationship between ice cream sales and homicides sounds preposterous; it is not likely that eating ice cream creates an urge to kill. Rather, it may be more relevant to consider a type of confounding variable in which a third variable, like temperature, which influences both eating ice cream and homicides. Research shows that both variables rise as a result of hot weather: Ice cream is an appealing way to cool down, and people are more likely to be outside and in greater contact with one another when it is hot. Simply knowing that there is a relationship between two variables doesn't tell us why that relationship exists.

Tuskegee syphilis study (1932-1972). The mistreatment of participants in this study was a critical reflection point in developing a consensus of guidelines for the treatment of all research participants in the United States.

Over 600 African-American men, including 400 known to have already acquired syphilis, were recruited to participate in the study with the promise of free meals, medical treatment for "bad blood" (a generic term for a variety of ailments-bodily disorder or chronic disease), and burial insurance. Unfortunately, the researchers' only goal was to follow the time course of the disease—they had no intention of treating participants for their "bad blood." Over the 40-year span of the study, researchers misled participants about the actual purpose of the study and denied them medical treatment, despite numerous medical advances in the treatment of syphilis during this time. This negligence ultimately led to the preventable deaths of hundreds of participants and needlessly contributing to the spread of syphilis. In 1972, the New York Times released a story about the Tuskegee syphilis study, and the public reacted in shock. Shortly thereafter, the government moved to establish federal ethical principles and guidelines outlining how all researchers should conduct research studies.

Participant Observation

Participant observation is a form of naturalistic observation in which the observer becomes a participant in the group being observed. Your text provides an excellent example of participant observation. Sometimes the only way to find out about a group of culture is to be immersed in it. For example, you cannot generally find out information about cults because they are secretive in nature and will only communicate with other cult members. There is a famous case in the 1950's of a cult called The Seekers who believed that there was going to be a gigantic tidal wave that would kill mankind; however, members of the group were going to be save by a flying saucer from outer space that would come and take members to safety on the alien planet. Several social psychologists and graduate students posing as other people with different backgrounds were able to join the cult and observe all that happened over the course of the preparation for the date of global catastrophe, the events on the night the flying saucer was supposed to land (but clearly did not), and the aftermath of the predicted event that failed to occur. ADVANTAGES OF PARTICIPANT OBSERVATION: Researcher interacts as a member of population they want to learn from. Allows for different research insights from the participant's perspective DISADVANTAGES OF PARTICIPANT OBSERVATION: May be subject to biases or interpretation. Observations may not be repeatable

socially desirable bias

Participants respond to questions in ways that would be seen as acceptable by others. In this case, the bias is not indiscriminate, but participants respond in specific ways that they believe would be seen as acceptable by others. For example, many people would be hesitant to admit to illegal or immoral behavior, especially if the survey results are not kept confidential.

Quasiexperimental designs:

Quasiexperimental designs are not considered true experiments because of the inability to randomly assign participants to the experimental and control groups (for example, if age is the variable of interest). In quasi-experimental or mixed designs: Researchers make use of groups that already exist, rather than randomly assigning participants to experimental groups. Quasi means "almost", so a quasi-experimental design is similar to but not quite a true experiment. When participants cannot be randomly assigned one of the IV conditions, it is considered a Quasi-experiment. This can happen with existing groups (e.g., comparing classes, existing work groups).

Principle D: Justice Pt.2 -- Practical reasons to limit participation in a research activity...

REASONS) A study on child development might only include children within a small range of ages because it captures how children perceive, react, or behave at that particular time. In this case, age is an (inclusion criterion)—a participant attribute that is essential to answer the research question. Conversely, (exclusion criteria) are any attributes that would prevent participation because they cannot address the research question. For example, adults would not be included as participants in a child development study because they are not a part of the age range that is being studied. The combination of inclusion and exclusion criteria form a study's (eligibility criteria), a set of characteristics shared by all participants that ensure that those participating will meaningfully help to address the research question. DEFINITIONS) a.) Inclusion criterion-- An attribute of participants that is necessary to be a part of a research study. b.) Exclusion criteria-- An attribute of a person that would prevent them from participating research study. c.) Eligibility criteria-- The combination of inclusion and exclusion criteria to create a set of characteristics shared by all participants that ensure that those participating will meaningfully help to address the research question.

Random selection versus random assignment

Random selection is the idea that everyone in the population of interest has an equal chance of being selected. If the sample is representative of the population, then after the research is conducted the findings (for the sample) can be generalized to the population. Thus, you can makes inferences about the populations based on the findings in the sample. Random assignment is the process of assigning subjects to the experimental or control groups in a random fashion, so that each subject has an equal chance of being in either group.

Three commonly used measures of the spread of data are:

Range, variance, and standard deviation

Respect for People's Rights and Dignity: FACEBOOK

Research in controlled laboratory settings has examined how emotional states, like joy or sadness, can be affected and transferred from one person to another through the process of "emotional contagion" (kind of like a behavioral version of "catching a cold" from a close friend). We have a pretty good understanding of this process in a laboratory setting, but researchers wanted to know if this would extend through virtual social networks, like Facebook. For one week in January 2012, researchers changed (or manipulated) the amount of positive or negative information in 689,000 users' news feeds. Some people saw more posts with positive emotional words, while others saw more negative emotional content on their news feeds. People who saw more positive events in their news feeds were more likely to create a few more positive posts of their own, whereas those who were exposed to more negative posts were more likely to create more negative posts. So, just like in the lab, the contagiousness of emotions extends to social media.

The story of Henry Molaison is a good example of a case study because:

Researchers studied him and gained valuable information about memory that could be used to formulate hypotheses and generate future research.

The Tuskegee researchers violated this ethical principle when they failed to tell participants about the true nature of the study when recruiting participants.

Respect for People's Rights and Dignity

From the David Rosenhan video, under what diagnosis were his pseudopatients discharged from the hospital?

Schizophrenia in remission

Imagine that we are interested in how maternal separation affects stress early in life. To explore this relationship, we separate young rat pups from their mothers for 15 minutes per day and measure corticosterone levels (a hormonal marker of stress) just before returning the pups back to their mother. What is the INDEPENDENT variable?

Separating rat pups from their mothers An independent variable is what an experimenter manipulates, and the artificial condition manipulated here is that the rat pups are removed from their mother to see how stressed the mother is by this separation.

In what type of sampling do all members of a population have an equal chance of being selected?

Simple random sampling

Single-subject experimental design

Sometimes it is necessary or helpful for a researcher to study one single participant. For instance, an individual with developmental disabilities may engage in self-injurious behaviors (SIB). In this situation, the researcher might design a behavioral program to reinforce behaviors incompatible with the self-injurious behaviors, as well as to eliminate or reduce conditions during which the self-injurious behavior was more likely to occur. Some of these designs use what is called an ABAB reversal design, in which a baseline for the behavior is recorded (A), followed by an intervention (B), followed by removal of the intervention strategy to determine the frequency of the behavior without the intervention (A), followed by re-implementation of the intervention.

Which of the following is not a measure of central tendency?

Standard deviation

Milgram's Conformity Experiment: An Example of Research Deception

Stanley Milgram, a psychologist at Yale University, was fascinated by the post-World War II Nuremberg war criminal trials. Many defendants justified killing countless people by claiming that they were merely following commands of their superiors. That is, the soldiers were simply doing what they were told to do. For a moment, consider how you might react to such an order. Most people would intuitively answer with a full-stop "NO." Milgram, however, wanted to know if there could be any truth to this "obedience" defense. In 1961, Milgram created an experiment to test how far people would go to obey an instruction provided by an authority figure. Before the experiment, experts estimated that fewer than 1% of a population would willingly participate in the death of others. Milgram recruited 40 male participants from a local newspaper advertisement to participate in a study of memory. During the experiment, participants were led to believe that they would help to teach a list of word-pairings to another research participant, who was actually a CONFEDERATE (another researcher who is acting like a participant). The confederate began to complain of the pain associated with the shocks and their desire to end the experiment, even yelling that he had a heart condition at a certain point. At the 300 volt shock, the confederate would physically bang on the walls and demand to be released. At some point during these shocks, many teacher-participants began to object to the experimenter. Milgram's study surprisingly revealed that 100% of participant delivered shocks up to 300 volts, and 65% continued to deliver shocks up to the maximum 450 volts. Milgram noted that most of the participants strongly objected to delivering the shocks, to the point of showing significant distress, but continued to follow orders all the way to the end. Milgram's research gave support to the "obedience" defense by demonstrating that most people are likely to follow orders by an authority figure, even if it means killing another person.

To definitively support a hypothesis, researchers must demonstrate that the results have ______________.

Statistical significance

Describing Data: Central Tendency

Statistics allow researchers to explain and describe the data. These types of manipulations are also known as descriptive statistics. This includes information like the mean, median, and mode and the frequency of certain demographics (e.g., 51% of participants were male). In addition to describing the data, we want to determine whether there are real differences between the independent variable condition so that we can make inferences about the causal relationship between the IV and DV, which is referred to as inferential statistics

What type of random sampling first divides members of a population into different groups before selection?

Stratified random sampling

Which of the following is an example of the Hawthorne effect?

Students came to more classes when they knew attendance would be taken.

Test-Retest Reliability:

Test-retest reliability measures temporal stability, which is the reliability over time. To determine test-retest reliability, the test is administered to a group of participants on two testing periods that is separated by some span of time. In the example above with stepping on a scale, the time interval was mere seconds. However, when answering questions on a measure, the time interval needs to be long enough so that participants are not simply responding from memory of the former answers, but not so long that other factors have changed one's knowledge or state of being. For example, if using test-retest on a measure of depression, the time needs to be long enough so your responses are not simply based on remembering your prior answers, but not so long that you may have gotten treatment or simply the depression resolved. With constructs that are highly dynamic (changing), other forms of reliability are often used. There are stable characteristics, such as personality traits and intelligence that are not believed to change over time. With stable constructs (concepts), test-retest reliability may be an appropriate means to help establish the reliability of the measure. Administration: Same participants Same test Two testing periods Period of time elapses between test (time 1) and retest (time 2) Scores at time 1 are correlated with scores at time 2 Correlation (r) should be above .70

Deception (Special Ethical Considerations)

The act of withholding information about the purpose and procedures of the study during the informed consent process. Researchers may feel that informing participants of the real intent of their research may change the way participants react during the experiment, thereby affecting the outcome of the study. For example, imagine a researcher is interested in understanding how the presence of others can influence your behavior and make you do things that you would not normally do. If the experimenter brought this to your attention before the experiment, this information would likely influence the decisions you make in key moments during the experiment. In this case, the researcher would be unable to capture the true nature of your behavior. As a result, some research experiments may seek IRB approval to engage in participant deception

The term 'beneficence' would best apply to which of the following?

The research benefits outweigh the costs that participants may experience

In the Hawthorne study, what was one change that was mentioned?

The amount of lighting in the work environment

rationalism

The belief or theory that reason is the key source of knowledge.

Principle D: Justice

The concept of justice strives to establish "equality" in the research process. Specifically, those people who participate in the research process should also be the same people who stand to benefit from the research outcomes. Justice is explicitly stated because researchers have historically included or excluded populations from participation in research. For example, women and children have historically been treated as vulnerable populations and unreasonably excluded from participation in clinical research. As a result, important research on the effects of medical treatments has often been collected from male-only populations and then generalized to women and children (Dresser, 1992). This is problematic, because there are fundamental differences between the sexes and people of different ages that may affect the efficacy and safety of treatments. For reasons like this, researchers should not include or exclude any group from participation for reasons that are unrelated to the study.

fidelity

The ethical principle of developing trusting relationships between researchers and participants.

Dependent variable (DV), or outcome measure

The experimenter counts or measures. In our experiment, we expect that aggressive behavior will be measurably greater in our group that plays violent video games. If the independent variable is the cause of change, then the dependent variable is the effect. Since the effect depends on the cause, what is measured is always called the dependent variable.

Generalization is the external validity of how the results from an experiment can apply to other settings, other people, and other time periods.

The external validity of a finding speaks to the degree to which a result can be applied beyond the scope of the experiment. Do the results of the experiment apply in the real world? Replication not only serves to establish internal validity but can also play a key role in establishing external validity. We can be more confident in the external validity of an experiment if the same experiment can be replicated in different settings, populations, and contexts.

What is not true of the following data set: {3, 4, 5, 6, 7, 7, 10}?

The median is 7

Let's say we're really interested in a new drug that claims to enhance memory. To test this claim, we could compare memory scores between two random samples of people where one group takes the hypothesized memory-enhancing drug and the second group does not.

The memory drug is our independent variable. In this case, we are creating two groups as a basis for our comparison. In research, the group that receives the treatment of interest (the memory drug) is called the experimental group. The other group, called the control group, is treated nearly identically to the experimental group but it does not receive the drug of interest. Our dependent variable and point of comparison between groups is how well each group performs on a memory test. We must also take into account the power of the mind and how it can influence our feelings and behavior. The mere thought of taking a drug that enhances our memory may lead to subtle psychological effects that make us pay closer attention to what we are memorizing, be slightly more alert, and most importantly perform a little better on the memory test. This effect is real, we are all susceptible to it, and it is called the placebo effect

According to this "The Magic of the Placebo" TED Talk, what is the main connection between magic and the placebo effect?

The placebo is felt even when you know it's fake.

Principle C: Integrity

The principle of (integrity) states that psychologists should engage in accurate, honest, and non-biased practices in the science, teaching, and practice of psychology. For example, psychologists should always strive to communicate results to colleagues and the public accurately, without making up data (fabrication) or manipulating research data (falsification). DEFINITIONS) a.) Integrity: An ethical principle that psychologists should engage in accurate, honest, and non-biased practices in the science, teaching, and practice of psychology.

Informed Consent

The process by which research participants learn about and understand the purpose, benefits, and potential risks of participating in a research study. If a participant is about to take part in a social stress experiment that might make them feel uncomfortable around others, they should be told in advance not only so that they do not feel "tricked" or deceived by the researcher, but more importantly because the individual may experience negative and unexpected consequences. For instance, a participant who has a history of anxiety problems might not want to take part in a study designed to produce stress. THIS MEANS: Participants give permission to participate in a study when all the details and risks of study participation are known

Reliability is a necessary but not sufficient condition for validity.

The statement can be found in many textbooks. It is essential that consumers of research, which typically include some form of measurement, understand that difference between reliability and validity. We already discussed that reliability is the consistency of a measure (across time, across forms, within the measure itself, and between raters). Validity is the accuracy of a test its appropriate use. It is important to note the following: (1) A test can be reliable, but not valid (2) If a test is not reliable, it is useless! Remember, validity accesses the appropriate use of a test. So a test may be valid in certain situations or settings but not others. For example, the Eating Disorders Inventory II (EDI-II) is valid predictor of eating disorders. However, the EDI-II is not a valid indicator of friendliness.

Chapter 2, Recap Pt. 1

The steps of the scientific method are (1) identifying the problem, (2) gathering information, (3) generating a hypothesis, (4) designing and conducting experiments, (5) analyzing data and formulating conclusions, and (6) restarting the process at step 3 by taking what you've learned into consideration. The difference between naturalistic and participant observation is whether the researcher is a part of the environment while making their observations about it. Bias can appear in observational research in many ways, including when participants change their behavior in response to being observed (known as reactivity or the Hawthorne effect) and when multiple observers disagree about what they've observed. Case studies are an in-depth way to gather a large amount of detailed information about a single person or a handful of individuals; however, case studies may not be generalizable to larger populations. Populations need to be sampled effectively, preferably using random sampling techniques; sampling error/bias can occur when the people who participate in a study are not representative of the intended population. The way people respond to questions in research studies is influenced by multiple factors, including but not limited to the wording of questions, the desire to answer in socially desirable ways, a general tendency to agree or say yes to questions, and a tendency to think of ourselves as better than average. Five ethical principles have been developed by the American Psychological Association (APA) to guide research with human subjects: (1) beneficence and non-maleficence, (2) fidelity and responsibility, (3) integrity, (4) justice, and (5) respect for people's rights and dignity. Ethical research in psychology should strive to have the most potential benefits to society with the fewest potential harms, not take advantage of participants, and be truthful with both participants in the study and the wider scientific community.

Strength of a Correlation

The strength of a correlation coefficient is becomes stronger as the points on a scatter plot get closer to the imaginary line that you could straight line one would draw that best encompasses the points on the graph - this is known as the line of best fit. Remember, the values of r range between -1 to +1. Correlation coefficient General Interpretation .8 to 1.0 Very strong relationship .6 to .8 Strong relationship .4 to .6 Moderate relationship .2 to .4 Weak relationship .0 to .2 Weak or no relationship

acquiescent response bias

The tendency for participants to agree or respond "yes" to all questions regardless of their actual opinions. (otherwise called "yea-saying"). Acquiescence refers to a tendency for participants to indiscriminately "agree" with most if not all items on a survey regardless of their actual opinion (Krosnick, 1991)

response bias

The tendency for people to answer the question the way they feel they are expected to answer or in systematic ways that are otherwise inaccurate.

illusory superiority

The tendency to describe our own behavior as better than average.

Students attending a class are asked to listen to a lecture under three different levels of illumination while researchers record signs of attention. What is the independent variable in this statement?

Three different levels of illumination

correlation coefficient MATHEMATICALLY explained

The value of a correlation coefficient ranges from (-1 to +1). Keep in mind that the positive and negative signs indicate the direction of the relationship, whereas the absolute value of the correlation (regardless of the +/- sign) is the magnitude or strength of the correlation. As the coefficient gets stronger, the value approaches 1.0 (positive or negative)—remember that the directionality is unrelated to strength. perfect positive correlation (r = +1.0) perfect negative correlation (r = -1.0) ^^^All points fall on a straight line. Thus, as the correlation gets stronger, the coefficient gets closer to +1 or -1. When there is no relationship: (r = 0 or numbers close to zero) ^^^There is no relationship between variables. Note that stronger relationships have data points that cluster around the line of best fit.

Independent variable (IV)

The variable that the experimenter will manipulate, and it must contain at least two levels. In the example above, the two groups are violent video game players and a control group that only plays non-violent video games. In this case, the independent variable is the type of video games people play (violent or non-violent). It's easy to remember that the independent variable always comes first, before any measurement is taken, and is what we think will cause a change in our experiment. Without an independent variable, this would not be an experimental measure.

Following the successful (and ethical) collection of data, researchers must decide how they want to analyze and explore this information.

Their approach will depend both on the study design and research question. When researchers conduct observations, case studies, and surveys, they are often looking to ~identify relationships that exist between two or more variables~ One way to quantify this relationship is through (correlation). Here, we are looking for some relationship to show that as one variable changes, so does another. Correlation: A measure (denoted as 'r') that captures the direction and strength of a relationship between variables.

Methods of Determining Reliability

There are a number of different ways in which reliability is assessed, including the following: Test-retest reliability (temporal stability) Alternate forms reliability (form stability) Internal consistency reliability (item stability)- split-half reliability- Cronbach's alpha Interrater reliability (interrater agreement)

Principle E: Respect for People's Rights and Dignity

This principle states that each person is valued in the research process and that researchers should take measures to respect and protect participants' rights, PRIVACY, and WELFARE. In the practice of research, this means that researchers should communicate openly and honestly about the details of the study before asking for participants' consent to participate in the research process. This also includes a requirement for respect of privacy and confidentiality of all participants.--It is important to ensure that data are kept private and even made anonymous to ensure that identifying information cannot be traced back to an individual. Respect for people's dignity also includes understanding the vulnerabilities of participant populations (e.g., socioeconomic status, religion, race, disability) and taking measures to ensure that participants are not coerced into participating in an experiment that they otherwise might not feel comfortable doing. For example, compensating research participants with money or course credit is a common practice in psychology research, but the amount of compensation should be reasonable and not an excessive amount that would motivate people to participate in activities they would not otherwise feel comfortable with.

Principle A: Beneficence and Non-maleficence

This principle states that research should strive to do good (beneficence) and avoid creating experiments that can intentionally harm (maleficence) participants. Psychologists must carefully weigh the benefits of the research against the costs that participants may experience and put in place safeguards to protect the mental and physical well-being of research participants. DEFINITIONS) a.) Beneficence: A concept of research ethics whereby researchers strive to do 'good' in a research study. b.) Maleficence: The act of doing harm.

In 2006, Roediger and Karpicke decided to conduct a practical experiment on the effect that tests (the independent variable) had on the memory recall (dependent variable) of relevant educational material. They hypothesized that repeated testing of educational material should lead to greater recall of information than simply studying.

To test this hypothesis, the researchers recruited a random sample of undergraduate participants and asked them to read a passage of text. Participants were then randomly assigned to two different groups. The first group, our experimental group, was asked to recall facts and details of the passage. That is, our experimental group was tested. The second group, our control group, was not tested but was asked to re-read the passage for an additional study period. In this case, we have just imposed a difference between the groups (our independent variable): One group was asked to recall information while the other was not. At this point, the researchers have exposed groups to two different types of learning experiences. If the "testing effect" hypothesis is real, we should see an improvement in recall in later testing. If the hypothesis is false, we should see no differences between groups, or perhaps a decrease in recall compared to our control group. The experimenters then measured student's ability to recall the passage either five minutes, two days, or even one week later. The passage of time is important because it helps us understand the short- and long-term effects of taking a test. Notice on the graph that our two independent groups are made distinct by different colored bars, with yellow bars for our experimental group and red bars for our control group. It is believed that "memory" or "recall" of information will be dependent on whether or not students are placed in the control or experimental group. Participants in the control group, who were given an additional five minutes of studying, seemed to have a slight advantage in the immediate recall of information. However, when recall of information was delayed by a couple of days or even a week, the participants in the experimental group recalled around 15% more information. That is, performance in the long term is better after testing than after studying. In this case, researchers manipulated two experiences that led to a change in behavior, thus allowing them to conclude that testing caused better memory retention in the long term. Using an experiment, we are finally able to draw a causal relationship between variables. The conclusion and observation of this experiment received a great deal of attention, and other researchers began to ask even more questions about the testing effect. In this text, you are frequently asked to recall information not because we want to assess you, but because we want to improve your learning.

A case study can include more than one person.

True

The location where data are collected may create alternative explanations for any results that are obtained.

True

Alternate Forms Reliability:

Two forms of the same test are developed, and to the highest degree possible, are equivalent in terms of content, response process, and statistical characteristics. One form (e.g., form A) is administered to examinees, and at some later date, the same examinees take the second form (e.g., form B). Scores from the first form of test are correlated with scores from the second form. If the scores are highly correlated (r), the test has form stability. Alternate forms reliability shows consistency across different forms of the same test. Some disadvantages to alternate forms (also known as parallel forms reliability) is that it is time consuming and difficult to develop two forms of the test that are supposedly measuring the same construct equivalently. There may be content sampling error if the content of the questions of one form vary from the second form.

Extraneous variables are:

Unwanted variables that can affect the measurements we are interested in

V W Z Vocab

V1. vulnerable populations -- Any group of individuals who may not be able to provide free and informed consent to participate in research. V2. volunteer bias -- A bias whereby only a motivated fraction of a population respond to a survey or participate in research. W1. wording effects --The influence of language, or wording, on people's responses to survey questions. Z1. zero correlation -- Two variables that exhibit no apparent relationship.

Validity: The Accuracy and Use of a Test

Validity is a measure of the accuracy test and assesses whether a measure is actually measuring what it professes to measure. The validity of a test also has to do with the use of a test. For example, the Beck Depression Inventory (BDI) may be a valid indicator of level of depression in an individual, but if someone used the BDI to assess intelligence, that would not be a valid use of that measure. It is important to note that although there are many different forms of validity that we will consider, the type of validation method largely depends on the intended use of a test. Define: Validity is the extent to which a test or inventory measures what it is supposed to measure. Validity answers the following questions: Are you measuring what you think you are measuring? What does the test score mean?

Chapter 2, Recap Pt. 2

Vulnerable populations (including those with impaired decision-making skills and those who are vulnerable by virtue of their circumstances) must be treated with particular care; informed consent is especially important in these groups. Deception in psychological research is only warranted in special circumstances, and participants must be fully debriefed about any deception that occurred after they finish participating in the study. A correlation describes the relationship between two or more variables and can be positive, negative, or zero (unrelated). Correlations have both strength and direction; strength describes how closely two variables are related, while direction describes whether the variables increase and decrease together (a positive relationship) or are inversely related, meaning that if one increases the other variable decreases (a negative relationship). Correlation coefficients are calculated to describe the strength and direction of a correlation. Correlation is not the same as causation: At times, correlation coefficients are misleading or confounding variables can make two variables appear causally related when they, in fact, are not.

Create Hypotheses and Experiment for the claim: "Playing violent video games makes people more aggressive."

We could conduct an experiment by controlling how much exposure people have to violent video games and then measuring whether it has an effect on aggressive behavior. In this case, a testable hypothesis that predicts a specific outcome might be: "People who play violent video games will exhibit more aggressive behavior than people who do not play violent video games." ^^^^^^^^^^^^^^^^^^ While more descriptive, this hypothesis still lacks specificity and has not yet defined what is meant by "aggressive behavior." An Operational Definition is how a researcher decides to measure a variable. Aggression could include behavior like physical aggressiveness (the number of hits, kicks, bites, or pushes) or verbal intimidation (how many swear words are directed at others). How a variable like aggression is operationally defined might depend on the ease of measurement, the strengths and weaknesses of each measure, and even what measures other researchers have used. For instance, physical aggressiveness may be easier to measure and has been previously used in similar types of studies. A more precise hypothesis would then be: "People that play violent video games will hit, kick, bite, or push others more frequently than people who do not play violent video games." This is our experimental hypothesis. It is what we expect to find if this idea is correct. This statement is consistent with prior observation and is simple and specific. The hypothesis can be both tested (measured) and falsified if we do not see more aggressive behavior.

Principle B: Fidelity and Responsibility

When people agree to participate in experiments, they are entrusting themselves to the researcher. In turn, the principle of fidelity and responsibility inspires researchers to maintain that trust. The word FIDELITY is often associated with the meaning "loyal" or "faithful." In the context of research, this means that researchers should be honest and reliable with participants. For example, if a study is known to include potential risks of participation, like making participants feel embarrassed or upset, the psychologist should let people know ahead of time so they are prepared for what to expect and can make an informed decision whether to participate or not. Psychologists also have a responsibility to hold themselves and their colleagues to high standards of conduct and take action if needed. For example, psychologists have a RESPONSIBILITY to PROTECT the WELL-BEING of participants by intervening if they see any situation that may harm participants.

Concept of an illusory correlation (from the root word illusion.)

When two events happen closely in time they are often falsely believed to be related. When pregnant, I wanted a snack to eat before going to bed to help ward off the nausea. I was going to eat a banana (which I don't really like but know they are a good source of potassium and I was trying to eat healthy. When I asked my husband to kindly get me a banana, he very seriously warned me that it was "dangerous" to eat bananas before bedtime because they are too heavy and that his Great Uncle had eaten a banana and died in his sleep.

Direction of Correlations) POSITIVE

When two variables are positively correlated, the variables change in the same direction; that is, As one variable increases, the other variable also increases, and as one variable decreases, the other variable also decreases. When creating a scatterplot with positively correlated variables, the data points appear to cluster around a line from the bottom left to the top right. For instance, height and weight are positively correlated. In general, as height increases, so does weight.

Direction of Correlations) NEGATIVE

When variables are negatively correlated, an increase in one variable leads to a decrease in the other. A plot of negatively correlated variables would appear around a line extending from the top left to the bottom right. For example, did you know that using computers during lectures could hurt your grades? In this case, doing more than one thing (such as shopping, looking at social media, etc.) on your laptop during a lecture may lead to lower test scores. In this negative correlation, more of one thing is correlated to less of another thing.

Internal consistency Reliability (IC)- Cronbach's Coefficient Alpha:

With the availability of advanced statistical software, like SPSS, Cronbach's alpha is an easy yet highly sophisticated form of IC reliability. Each item on the test/measure is correlated with every other item; the average of all inter-item correlations = alpha. So if there were 10 items on a measures, item 1 would be correlated with each other item: 2, 3, 4, 5, 6, 7, 8, 9, 10; item 2 would be correlated with items 3, 4, 5, 6, 7, 8, 9, and 10 (note it would not be correlated with 1 because this correlation between 1 and 2 was previously done); item 3 with items 4, 5, 6, 7, 8, 9, and 10); and this would continue until each item were correlated with every other item. Consider that most measures have more than 10 items and the number of inter-item correlations becomes exponentially larger with an increase in sample size. You can imagine that if there were to be calculated by hand, it would take a very long time. However, with the use of statistical software SPSS to calculate this, it can be calculated in seconds. When measuring IC reliability and other forms of reliability, an increase in the number of items in a measure can increase the measures reliability. In general, an acceptable level of internal consistency reliability is when the Cronbach's alpha is .85 or above.

The idea that a variable is quantifiable is the notion that

a numeric value can be assigned and that the value assigned is consistent (reliable) across different raters). For variables like video game playing, there are two condition that can be assigned a number (e.g., 0 = nonviolent video game; 1 = violent video game). The number itself is not that important (e.g., 0 and 1, 1 and 2, or 100 and 200) - the idea is that if you know the condition is nonviolent video games, the same number is assigned a 0 (or whatever number is predetermine) is easy to reliably assign.

Internal Consistency Reliability: Internal consistency (IC)

is the consistency of the items within the measure. IC addresses whether a questionnaire/test measures the same construct (concept/idea) throughout the entire test. Internal consistency reliability is used when it is impractical to administer two separate forms of a test. With IC reliability the test is administered only once and measures item stability and consistency across items.

Complete this sentence: Ideally, if a study concluded that eating ice cream caused violence, it would have to ___________________________________.

randomly assign participants to groups eating more and less ice cream and compare rates of violence To manipulate a variable, we need at least two conditions (eating more ice cream versus eating less ice cream). We can randomly assign participants to each group to determine causation. We would then measure the violent behavior of participants in both groups.

Interrater Reliability:

refers to the degree of agreement between 2 or more raters. Interrater agreement/reliability is used when human judgment of another person's behavior or performance is involved. In the case of clinical psychologists, if they are using a reliable means of categorizing persons with mental illness, then you would expect high levels of agreement if you looked at the diagnoses given to a group of persons by two different clinicians. Some diagnoses have higher levels on interrater agreement than others. For example, clinician can more reliably diagnose depressive and anxiety disorders; however, the level of interrater agreement drops significantly when assessing personality disorders. Consider the types of problems that are created when persons are given different diagnoses by different clinicians? Which diagnosis is the "correct" diagnosis? This is very important as the diagnosis affects treatment planning, which may include the use of medications. It is important that a diagnosis be correct. If using measures that yield very little agreement between raters, then these measures are not useful.

An experimental psychology course asks all student to administer a questionnaire about classroom technology use. The approach being used here is best described as a(n) ______________ .

survey

Construct validity demonstrates

that you are measuring the construct that you think you are measuring. The construct validity of a measure is supported when scores on the measure are highly correlated with related constructs and are not correlated with unrelated constructs. The idea that the construct being measured correlates with related constructs (measures) is known as convergent validity. In contrast, divergent validity (or discriminant validity) is when the construct being measured does not correlate with unrelated constructs. Thus, one way of demonstrating construct validity is to show both convergent and divergent validity.


Set pelajaran terkait

Lección 2 Estructura 2.4 Numbers 31 and higher

View Set

CSET Subtest 1: Reading, Language, and Literature

View Set

Chapter 40: Fluid, Electrolyte, and Acid-Base Balance

View Set

OB GYN CTL 2nd/3rd Trimester Pathology P2

View Set

SAT 2 Cell Division- Mitosis and Meiosis

View Set

PF Information Literacy Lesson 3

View Set