AP Psychology Unit 2: Test #3

Hypothesis

a testable prediction, often implied by a theory -predictions about behavior that can be tested -theory: using observations to explain behavior

In a drug study, neither the participants nor the person distributing the pills knows who is receiving the new drug and who is receiving the placebo. This type of research design is said to be a(n) ___ study

double-blind

A testable prediction that drives research is known as a(n)

hypothesis

Researchers have discovered that individuals with lower income levels report having fewer hours of total sleep. Therefore,

income and sleep levels are positively correlated

Replication

is CONFIRMATION -must need operational definition; variable must be quantified

Mean

mathematical average of a set of #s. Add the scores and divide by number of scores

Which measure of central tendency is most influenced by outliers (data that is extremely different from other data in the set)? mean, median, mode, standard deviation, histogram

mean

Skewed Distribution

most scores or data fall on one side of the scale and there are very few scores on the other side -when one data point is extremely different from the others, it is Ann outlier which can skew results -**the median will be a better descriptor of data when the mean is impacted by outliers

Normal Curve

the symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes. Most scores fall near the average, and fewer and fewer scores lie near the extremes.

Hindsight bias

the tendency to believe, after learning an outcome, that we would have foreseen it -we knew it all along

Population

those in a group being studied, from which samples may be drawn

Theory

using observations to explain behavior

Which of the following correlation coefficients represents the strongest relationship between 2 variables?

-0.85

Practice FRQ: A researcher is conducting a study and wants to ensure that the sample chosen to participate will yield good results. -Why is it better to have a large sample of data instead of a small sample? -What happens to reliability as sample size increases?

-A larger sample will be less variable (for ex., a large sample from a population w/ 40% women and 60% men will be more likely to be close to that demographic breakdown than a smaller sample). -As the sample size increases, the results are more likely to be reliable (represent the opinions) of the population as a whole.

8-3 review: How do we describe data using the three measures of central tendency?

-A measure of central tendency is a single score that represents a whole set of scores. Three such measures are the MODE (most frequently occurring score) the MEAN (arithmetic average), and the MEDIAN (the middle score in a group of data).

Dr. Cheema is interested in studying the prevalence of cheating on exams at her local high school. Describe one disadvantage of using each of the following research methods to study this topic: -case study -naturalistic observation -survey

-Case study: If only one individual is interviewed and if this individual could be atypical, this could lead to misleading research. These results may not be generalizable for the whole student body. -Natural observation: It would be impossible to understand the causes and reasons for students to cheat and their methods as no variables could be controlled as they are testing in their natural classroom environment. -Survey: Although a survey is utilized to learn why students cheat, students who cheat would most likely lie, and the results from the survey would be unrealistic.

6-1 Review: What does it mean when we say two things are correlated, and what are positive and negative correlations?

-Correlation is the degree to which two variables are related, and how well one predicts the other. -In a positive correlation, two factors increase or decrease together. -In a negative correlation, one variable increases as the other decreases. -A correlation coefficient describes the strength and direction of a relationship between two variables, from +1.00 (a perfect positive correlation) through zero (no correlation at all) to -1.00 (a perfect negative correlation) -The relationship may be displayed in a SCATTERPLOT, in which each dot represents a value for the two variables.

How do psychologists use case studies, naturalistic observations, and surveys to observe and describe behavior, and why is random sampling important?

-Description methods, which include case studies, naturalistic observations, and surveys, show us what can happen, and they may offer ideas for further study. -The best basis for generalizing about a population is a representative sample; in a random sample, every person in the entire population being studied has an equal chance of participating. -Descriptive methods describe but do not explain behavior, because these methods do not control for the many variables that can affect behavior.

4-1 Review: How do hindsight bias, overconfidence, and the tendency to perceive order in random events illustrate why science-based answers are more valid than those based on common sense?

-Hindsight bias (the I knew it all along phenomenon) is the tendency to believe, after learning an outcome, that we would have foreseen it. -Overconfidence in our judgments results partly from our bias to seek information that confirms them. -These tendencies, along with our eagerness to perceive patterns in random events, lead us to overestimate the weight of commonsense thinking. Although limited by the testable questions it can address, scientific inquiry can help us overcome such biases and shortcomings.

A local basketball team has won three championships in a row and is on a winning streak going into the final game. Explain how their fans might use the following to explain a loss in the final game: -hindsight bias: -overconfidence: -the tendency to perceive patterns in random events:

-Hindsight bias: After winning three championships, it should have been apparent that they would not be able to keep up their winning streak as a player might have been injured or not playing his best. -Overconfidence: The basketball team must be worn out from winning three championships, so fans expected them to win one more due to their winning streak. -The tendency to perceive patterns in random events: Since the team already won three championships, there would be no way that they could win another. An outcome of four wins in a row would not be possible, and a loss must be expected.

**Practice FRQ: Elena won the lottery last night. Afterward, she told her friends that she knew she was going to win. Her friends think that she is so lucky because she won the lottery last year as well. Explain how hindsight bias and the tendency to perceive patterns in random events apply to Elena's winnings.

-Hindsight bias: Elena knew today that she would win the lottery bc she did. If she hadn't won, she would not remember the "feeling" that she would win. -Pattern in random events: Elena's winnings are unconnected. The odds of winning make it seem like a person is "lucky" if they win, but the odds of winning the lottery twice are not that unrealistic when odds of winning are spread out across an entire population.

6-3 review: What are illusory correlations, and what is regression toward the mean?

-Illusory correlations are random events that we notice and falsely assume are related. -Regression toward the mean is the tendency for extreme or unusual scores to fall back toward their average.

Ms. Ledbetter wants to determine if the new review activity she developed will improve student performance on unit exams. She randomly separates 160 students into two groups. Group A reviews for the unit exam in the traditional manner they have always used. Group B participates in the new review activity. After reviewing both groups are given the same unit exam and their scores are compared. Explain how the following terms relate to this study: -independent variable -dependent variable -control group

-Independent variable is the review type: either the new review activity or the traditional review. -Dependent variable: Scores are dependent on the review type. -Control Group: Group A is the control group as they review in the traditional manner. Group B is the experimental group as they participate in the new review activity.

Researchers interested in studying stress gave 150 high school seniors a very difficult math exam. After the test, the researchers measured stress by examining physiological changes w/ extensive medical testing that included drawing blood samples. When the test was over, they shared the results w/ the students but did not publish individual data. Explain whether or not this study conforms to each of the ethical standards: -informed consent -debriefing -confidentiality -protection from harm

-Informed Consent: If the high schoolers consented to participating in this experiment, then the researchers conformed to this ethical standard. If the high schoolers did not give their consent to participate in this experiment that involves getting their blood drawn after taking a difficult math exam, then the researchers did not follow ethical standards. -Debriefing: The researchers conformed with the ethical standard of debriefing as they shared the results of the experiment with the students. -Confidentiality: As the researchers did not publish individual data, they maintained confidentiality. -Protection from harm: As the students were not exposed to uncommon procedures, the researchers conformed to the ethical standard of protection from harm. Many highschoolers take difficult tests often and get their blood drawn regularly.

8-4 review: What is the relative usefulness of the two measures of variation?

-Measures of variation tell us how diverse data are. Two measures of variation are the RANGE (which describes the gap between the highest and lowest scores) and the STANDARD DEVIATION (which states how much scores vary around the mean, or average, score) -The range offers only a crude measure of how much the data vary; the standard deviation is far better at giving researchers a clear understanding of variation is far better at giving researchers a clear understanding of variation. -Scores often form a NORMAL (or bell-shaped) CURVE

8-1 review: Why do we need statistics in psychology and in everyday life?

-Psychological researchers use statistics to measure variables and interpret results. -All of us benefit from a basic understanding of statistics, which helps us think smarter about medical advice and news reports of all kinds.

7-1 Review: How would you know which research design to use?

-Psychological scientists design studies and choose research methods that will best provide meaningful results. -Researchers generate TESTABLE QUESTIONS, and then carefully consider the best DESIGN to use in studying those questions (experimental, correlational, case study, naturalistic observation, twin study, longitudinal, or cross-sectional). -Next, psychologists MEASURE the variables they are studying, and finally they INTERPRET their results, keeping possible confounding variables in mind.

5-1 Review: How do theories advance psychological science?

-Psychological theories are explanations that apply an integrated set of principles to organize observations and generate hypotheses--predictions that can be used to check the theory or produce practical applications of it. By testing their hypotheses, researchers can confirm, reject, or revise their theories. -To enable other researchers to replicate the studies, researchers report them using precise operational definitions of their procedures and concepts. If others achieve similar results, confidence in the conclusion will be greater.

7-5 review: How do values affect psychological science?

-Psychologists' values influence their choice of research topics, their theories and observations, their labels for behavior, and their professional advice. -Applications of psychology's principles have been used mainly in the service of humanity.

7-2 review: How can simplified laboratory conditions illuminate everyday life?

-Researchers intentionally create a controlled, artificial environment in the laboratory in order to test general theoretical principles. These general principles help explain everyday behaviors.

8-2 review: What are descriptive statistics?

-Researchers use DESCRIPTIVE STATISTICS to measure and describe characteristics of groups under study, often using a HISTOGRAM to display data. -Descriptive statistics include measures of central tendency and measures of variation

8-5 review: What are inferential statistics?

-Researchers use INFERENTIAL STATISTICS to determine the probability of their findings being also true of the larger population. -Inferential statistics include ways of determining the reliability and significance of an observed difference between the results for different groups.

Why do psychologists study animals, and what ethical guidelines safeguard animal research subjects?

-Some psychologists are primarily interested in animal behavior; others want to better understand the physiological and psychological processes shared by humans and other species. -Government agencies have established standards for animal care and housing. Professional associations and funding agencies also have guidelines for protecting animals' well-being.

Practice FRQ: Nonhuman animals are often subjects in psychological experiments. Provide three reasons why a psychologist might use animals instead of humans in a study.

-Some researchers use nonhuman activities bc they are interested in understanding the animals themselves, including their thinking and behaviors. -Others use nonhuman animals to reduce the complexity that is part of human research. They hope to understand principles that may be similar to those that govern human psychological phenomena. -Researchers also study nonhuman animals in order to apply the findings in ways that will help both humans and the other animals.

The following data set includes information from survey research in a psychology course regarding how many hours each student in the class spent preparing for the exam. Student: Number of hours reported studying 1. 2 2 3 3 6 4 8 5 9 6 9 7 21 Examine the data and respond: -Identify the following from the data: range, mode, median -Explain why the teacher may wish to calculate the standard deviation for this set of data.

-The range is 19. -The Mode is 9. -The Median is 8. -The teacher may wish to calculate the standard deviation for this set of data as the range is extremely large due to an outlier of 21 hours reported studying. This outlier also affects the mean. The standard deviation would show how much scores vary around the mean score, but the outlier of 21 hours of reported studying will need to be excluded in order to obtain a more accurate understanding of the standard deviation

Practice FRQ: Researchers surveyed 800 high school students enrolled in AP Psych to determine whether students with higher score on anxiety scales had lower scores on standardized tests. Students with higher scores on anxiety scale were indeed found to have lower scores on standardized tests. Explain how each of the following terms or phrases applies to the situation described above: -Random sampling -Generalization -Correlation doesn't mean causation

-The researchers could use random sampling to choose the 800 students for their survey. The names, for example, be chosen in such a way (every fiftieth name of those taking the course) to ensure that every test taker has the same chance of being selected. -If the random sample is used, it will be representative of the wider population from which it was drawn. Thus, the researchers will be able to generalize the results from their sample to the wider population of AP Psych students. The results of the survey would only apply to AP Psych students, not high school students in general. -Even if anxiety and test scores correlate positively, the researchers would not be able to say that anxiety caused the lower standardized test scores.

Practice FRQ: A teacher was to know if nightmares are more common than dreams. He asks volunteers from his second-period class to report how many dreams they had last week. He asks volunteers from his third period class to report the number of nightmares they had last week. Describe two thins wrong with the design of this study.

-There is no hypothesis stated -In asking for volunteers, the teacher is taking a nonrandom sample that probably is not representative of the population of interest. -Neither dreams or nightmares are operationally defined, so they might be interpreted differently by later researchers.

6-4 review: What are the characteristics of experimentation that make it possible to isolate cause and effect?

-To discover cause-effect relationships, psychologists conduct EXPERIMENTS, manipulating one or more variables of interest and controlling other variables. -Using RANDOM ASSIGNMENT, they can minimize CONFOUNDING VARIABLES, such as preexisting differences between the EXPERIMENTAL GROUP and the CONTROL GROUP (given a placebo or different version of the treatment) -The INDEPENDENT VARIABLE is the factor the experiment manipulates to study its effect; the DEPENDENT VARIABLE is the factor the experimenter measures to discover any changes occurring in response to the manipulation of the independent variable -Studies may use a DOUBLE-BLIND PROCEDURE to avoid the PLACEBO EFFECT and researcher's bias. -An experiment has VALIDITY if it tests what it is supposed to test

8-6 review: How do we know whether an observed difference can be generalized to other populations?

-To feel confident about generalizing an observed difference to other populations, we would need to know that the difference was reliable and also significant -Reliable differences are based on samples that: -are representative of the larger population being studied -demonstrate low variability, on average -consist of many cases -We can say that an observed difference has statistical significance if the sample averages are reliable and when the difference between them is large.

Debriefing

-in some experiments, the true purpose can't be revealed bc it would influence the results -when temporary deception is necessary to the research, it must not be fully explained at the conclusion of the experiment

Correlation

-positive -negative -help predict events

Sampling Bias

-where was the survey conducted? -who was in the sample? Population: those in a group being studied, from which samples may be drawn Random Sample: a sample that fairly represents a population bc each member has an equal chance of inclusion

What is the range of the following: 12, 25, 33, 40, 80?

68

In a normal distribution, what percentage of the scores in the distribution falls w/in one standard deviation on either side of the mean?

68%

Which of the following questions is best investigated by means of a survey? a. Are people more likely to vote Republican or Democrat in the next election? b. Are violent criminals genetically different from nonviolent criminals? c. Does extra sleep improve memory? d. What is the best study technique for the AP exams? e. What role does exercise play in weight loss?

A

Which of the following is an example of hindsight bias?

Alliyah, after reading a definition on one of her flashcards, turns the card over to see the term, and then tells herself she knew what the answer was all along.

Why is an operational definition necessary when reporting research findings?

An operational definition allows others to replicate the study

Which of the following animal studies is most likely to receive approval?

Can dolphins learn simple language?

An individual with an exceptional memory is identified. For any given date, she is capable of recalling major events, the weather, and what she did that day. What research method is being used if a psychologist conducts an in-depth investigation of this individual using questionnaires, brain scans, and memory tests?

Case Study

Which of the following is most important when conducting survey research?

Choosing a representative sample

6-2 review: Why do correlations enable prediction, but not cause-effect explanation?

Correlations enable prediction bc they show how 2 factors are related--either positively or negatively. A correlation can indicate the possibility of a cause-effect relationship, but it does not prove the direction of the influence, or whether an underlying third factor may explain the correlation.

Which ethical principle requires that at the end of the study participants be told about the true purpose of the research?

Debriefing

2. Which method should a psychology researcher use if she is interested in testing whether a specific reward in a classroom situation causes students to behave better?

Experiment

6. "Monday morning quarterbacks" rarely act surprised about the outcome of weekend football games. This tendency to believe they knew how the game would turn out is best explained by which psychological principle?

Hindsight bias

After the student council election, a friend tells you he could have guessed who would be elected president. What psychological phenomenon might this illustrate?

Hindsight bias

3. In a perfectly normal distribution of scores, which of the following statements is true?

The mean, median, and mode are all the same number

While taking a standardized test with randomly scrambled answers, you notice that your last four answers have been "c." Which of the following is true concerning the probability of the next answer being "c"?

It is unaffected by previous answers. It is as likely to be "c" as any there answer.

A researcher looking for gender differences in 3-year-olds observes a preschool class and records how many minutes children of each gender play with dolls. She then compares the two sets of numbers. What type of descriptive research is she conducting?

Naturalistic observation

The tendency to exaggerate the correctness or accuracy of our beliefs and predictions is called

Overconfidence

4. Which of the following describes the placebo effect?

Participants in a drug study are given an inert pill instead of the drug and behave as though they were given the drug

Which of the following is an example of negative correlation?

People who spend more time exercising tend to weigh less

What must a researcher do to fulfill the ethical principle of informed consent?

Provide participants w/ enough information about a study to enable a rational decision about whether to participate.

Researchers are interested in finding out if voters are more likely to vote for congressional candidates who have more pleasant facial expressions. Starting at a random point, the researchers contact every 100th person on the voter list to ask about candidate facial expressions. Which method are the researchers using in choosing the people they will call?

Random Sample

The laboratory environment is designed to

Re-crate psychological forces under CONTROLLED conditions

The purpose of random assignment is to:

Reduce potential confounding variables

5. Which of the following represents naturalistic observation?

Researchers observe students' seating patterns in the cafeteria

1. A student is interested in knowing how widely the academic aptitude of college bound students varies at her school. Which of the following statistical methods should she use to determine how much students' SAT scores vary from the school's average SAT score?

Standard Deviation

7-4 review: What ethical guidelines safeguard human research participants?

The APA ethics code outlines standards for safeguarding human participants' well-being, including obtaining their INFORMED CONSENT and DEBRIEFING them later

In an experiment to test the effects of room temperature on test performance the independent variable is

The temperature of the room

A researcher calculates statistical significance for her study and finds a 5% chance that results are due to chance. Which of the following is an accurate interpretation of this finding?

This is not statistically significant

Statistical Significance

a statistical statement of how likely it is that an obtained result occurred by chance

Histogram

a bar graph that shows a frequency distribution -displays statistics

Standard Deviation

a computed measure of how much scores vary around the mean score 1. calculate mean 2. for each data point: subtract the mean and square the result 3. Calculate mean of all squared differences 4. Take square root of sum -shows whether scores are packed together (similar) or dispersed (varied) -Always positive. -Will be zero if all data values are equal -influenced by outliers

Confounding Variable

a factor other than the factor being studied that might influence a study's results -unique factor must be present in one of the groups (experimental or control) but not in other -can't be confounding if it occurs to same degree in both groups -random assignment is one method used to prevent confounding variables -age, sex, intelligence level, political beliefs, ethnicity

Random Sample

a sample that fairly represents a population bc each member has an equal chance of inclusion

Correlation Coefficient

a statistical index of relationship btwn 2 variables + correlated or - correlated

Placebo Effect

an inert treatment...like a pill w/out any medications inside

Random Assignment

assigning the participants to experimental or control group by chance

Operational Definition

carefully worded statement of the exact procedures (operations) used in a research study -variable would need to be quantified -Important bc: specifically define and allow replication

Survey

descriptive technique for obtaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group -Strengths: able to take a quick pulse of people's beliefs, behaviors, or opinions; able to include many cases -Weaknesses: response bias; wording effects skew outcomes; acquiring random sample is difficult; can't determine cause and effect

Case Study

descriptive technique in which 1 individual or group is studied in depth in hope of revealing universal principles -strengths: allow for examination of rare or unusual behavior and provides large amount of qualitative data and suggest directions for further study -weaknesses: atypical cases can be misleading; results from study may not be generalizable to larger group; can't determine cause and effect

Naturalistic Observation

descriptive technique of observing and recording behavior in naturally occurring situations w/ out trying to manipulate or control the situation

Validity

goal of experimental design; -experiment will test what it is supposed to test

Scatterplot

graphed cluster of dots, each of which represents the values of 2 variables -slope of points suggests the positive or negative direction of the relationship btwn 2 variables -the amount of scatter suggests the strength of the correlation -values on the x and y axis must be quantified

Inferential Statistics

numerical data that allow one to generalize- to infer from sample data the probability of something being true of a population

Experimental Group

subjects that receive treatment

Descriptive statistics _____, while inferential statistics______.

summarize data; assess if data can be generalized

Regression toward the mean

tendency for extreme scores or events to fall back to average

Illusory Correlation

the perception of a relationship where none exists or perceiving a stronger-than-actual relationship -superstitions