RM final2

Three principles of graphing:

1) clarity 2) precision 3) efficiency

All single-case experiments have the following characteristics:

(1) Only one sampling unit is studied (or very few) (2) Repeated measures are taken of the unit (a within-subject design) (3) Random is assignment is probably not possible

Life, Change, and Stress Holmes and Rahe (1967)

+ life stress: certain external changes occur in people's lives, people need to make psychological adjustments and there is a tendency for a higher incidence of illness Design: •Holmes and Rahe complied a list of 43 life events that people commonly feel are stressful. •This list was presented to 394 subjects, who were asked to rate each item on the list for the amount of stress produced by the event. •Subjects were instructed to assign a point value to each event relative to the 500 value given to "marriage". •Stress was operationalized as: the amount of time to psychologically readjust to an event relative to marriage. •They divided the average score by 10 to rescale the scale. •They divided the average score by 10 to rescale the scale. •What would marriage be on this scale?

Frequency Distributions

- A summary chart, showing how frequently each of the various scores in a set of data occurs - allow you to present an overall pattern of data. - presented as a Table or as a Graph.

Survey Research

- gathering primary data by asking people questions about their knowledge, attitudes, preferences, and buying behavior - the process of conducting research using surveys that researchers send to survey respondents (the data collected is then statistically analyzed to draw meaningful research conclusions)

point estimate

- single numeric quantities (i.e. "points") that are computed from sample data for the purpose of providing some statistical approximation to population parameters of interest - the value of the sample average; the sample average is the best estimator of the population mean

Blaise Pascal

- was a French mathematician, physicist, and religious philosopher - earliest work was in the natural and applied sciences - made important contributions to: + the construction of mechanical calculators + the study of fluids + clarified the concepts of pressure and vacuum by generalizing the work of Evangelista Torricelli - wrote powerfully in defense of the scientific method

Correlations that are strong are closer to what value?

1 & -1

What poses a threat to internal validity?

1) History 2) Maturation 3) Instrumentation 4) Selection

What is the purpose of randomly assigning the sampling units and how is this done?

1) Protects Against Bias: Random assignment provides a safeguard against the possibility of experimenters letting their preferences or opinions influence which sampling units will receive any given treatment. 2) Increases External Validity: Random assignments distributes the characteristics of the subjects across groups in an unbiased fashion. 3) Facilitates Statistical Analyses: Random assignment allows for certain statistical procedures to be used. 4) Random assignment can be accomplished in a number ways.

A common interval estimate:

95%

common interval estimate:

95%

method

: Explains in detail how the research conducted their study.

Alternative Hypothesis (Ha)

A certain variable does affect a dependent variable. E.g., A items are larger than B items on average Hypothesis in which there are nonzero effects and there are differences between treatments

Null Hypothesis (HO):

A certain variable has no effect on a dependent variable. E.g., there is no difference between A and B items. A statement of no difference or no relationship between variables; the statistical hypothesis.

interrupted time series design

A design in which the effectiveness of a treatment is determined by examining a series of measurements made over an extended time period both before and after the treatment is introduced. The treatment is not introduced at a random point in time. - a specific type of time-series designs in that there is a CLEAR BOUNDARY in the time periods you're interested in. That boundary is an "interruption" in the time series design. For example, you study positive emotions over time, and you're interested in seeing whether having a mindfulness intervention for a week boosts positive emotions. That intervention introduces an INTERRUPTION in the time you're examining; the time before the intervention can never be the same as the time after the intervention (if the intervention is effective). So you're essentially looking at a pre- and post- intervention effects of the mindfulness intervention on positive emotions.

positively skewed distribution

A distribution where the scores pile up on the left side and taper off to the right. - The mean will be higher than the median in a positively skewed distribution.

stratified random sampling

A form of probability sampling; a random sampling technique in which the researcher identifies particular demographic categories of interest and then randomly selects individuals within each category. - Allows for different elements to be taken into consideration by sampling randomly from each level of the variable (e.g., age). - Each level is referred to a stratum or cluster.

Say you conducted a correlational study. After calculating the correlation between two of your variables you found out that your Pearson's r = -.42 with a p value of .12. Which of the following conclusions accurately describes the relationship between your two variables?

A medium negative association that is non-significant

cross-lagged panel design (cross-lagged)

A method in which the same set of behaviors or characteristics are measured at two separate points in time (often years apart); six different correlations are computed, and the pattern of correlations is used to infer the causal direction. - some data are treated as though they are delayed values of an initial dependent variable.

Counterbalancing

A method of controlling for order effects in a repeated measure design by either including all orders of treatment or by randomly determining the order for each subject -refers to the systematic variation of the order of conditions in a study, which enhances the study's interval validity.

A stratified random sampling method is described as:

A method that allows for different elements to be taken into consideration by sampling randomly from each level of the variable

standard normal distribution

A normal distribution with a mean of 0 and a standard deviation of 1.

between-subjects design

A research design in which different groups of participants are randomly assigned to experimental conditions or to control conditions. - Different levels of the independent variable are given to different groups of subjects

longitudinal research

A research design in which the same individuals are followed over time and their development is repeatedly assessed.

two-factor design

A research study involving two independent or quasi-independent variables.

opportunity sample

A sample of participants produced by selecting people who are most easily available at the time of the study.

biased sample

A sample that does not fairly represent the population - the results of the survey may not reflect attitudes of the population. For instance, the mean score of the participants of the survey should come close to the mean score of the population.

simple random sampling

A sampling procedure in which each member of the population has an equal probability of being included in the sample.

Time-series designs

A type of quasi-experimental design in which only one group receives the intervention; an outcome is measured repeatedly over time - the effects of some treatment are inferred from a comparison of the outcome measures (DVs) obtained at different time intervals before and after treatment occurred

type 2 error

Accepting null hypothesis when you should have rejected it The probability of avoiding a Type II error is the statistical power of the test

What aspect of Phrenology made it a pseudoscience?

Advocates did not attempt to falsify its assumptions.

What are the two hypotheses used in Null Hypothesis Significance testing called?

Alternate/Null

nonequivalent group design

An experimental design whereby the researcher doesn't use random assignment, so the control group is not necessarily equivalent to the experimental group. - Nonrandomized research in which the responses of a treatment group and a control group are compared on measures collected at the beginning and the end of research - Traditionally these have at least one between-subjects IV - For instance A versus B might different states, different clubs, different classes, etc. Thus, the history of the groups might be different (a threat to internal validity).

A correlation coefficient with a negative sign before the value, like r = -.33 indicates:

An increase in one variable is associated with a decrease in another.

Researchers were wanting to see if participating in extracurricular activities was linked to depression scores. They sampled a set of students from a local high school and then asked the first set of students to recommend other students to participate in the study. The researchers asked the students if they participated in extracurricular activities and then had them take a test for depressive symptoms. After calculating their results, the researchers claim that participating in an extracurricular activity causes a decrease in depression symptoms. (2) Which of the following correctly describes a possible third variable that could be influencing the relationship between extracurricular activities and depression symptoms?

Both depression symptoms and extracurricular activities could be results of an unmeasured variable.

where is the dependent variable most typically labeled?

y-axis (ordinate)

How do scientist logically infer efficient causality?

Casual inference: (1) Co-variation (2) temporal precedence (3) internal validity

Occam's razor is used to address which criterion for acceptable hypotheses?

Coherence and parsimony

A variable that is split into two distinct categories is a _____ variable

Dichotomous

Selection

Different group in the pre- and post-test

Aserinsky was one of the first people to systematically investigate dreaming. In what stage of research did he observe that the eyes of infants were moving and speculate that these eyements maybe related to dreaming?

Discovery

If a researcher takes a categorical variable like gender and quantifies it by recoding male = 0 and female = 1, that researcher did what to their variables?

Dummy-Coded

When experimenters are expecting a certain outcome in their participants, so they unknowingly influence the outcome of their experiment to fit their expectations they are experiencing _____.

Experimenter expectancy effect

introduction

First section of regular text. It explains the topic of the study, lay out the theoretical and empirical background for the research, states the specific research questions, goals, or hypotheses for the current study.

Effect sizes tell researchers what?

How strongly related the variables are

Graphing principle efficiency:

If you have a story to tell, get to the point.

Graphing principle precision:

If you have a story to tell, make sure that it is presented accurately

Statistical power

In inferential statistics, the probability that a significance test will reject the null hypothesis when it is in fact false a measure of the likelihood that we will reject the null hypothesis, given that the null hypothesis is false significance tests increase in power with increasing sample sizes

Which range should be reported? (range or extended range)

In most cases, it doesn't matter which range that you report.

Researchers were wanting to see if participating in extracurricular activities was linked to depression scores. They sampled a set of students from a local high school and then asked the first set of students to recommend other students to participate in the study. The researchers asked the students if they participated in extracurricular activities and then had them take a test for depressive symptoms. After calculating their results, the researchers claim that participating in an extracurricular activity causes a decrease in depression symptoms. (1) Are the authors correct to assume causality in this situation?

No. Their study design does not meet all three criteria for inferring causality.

When a researcher is concerned that the participants who did not respond to their survey differ systematically from those who did respond to their survey they are concerned with:

Nonresponse Bias

dummy coding

Numeric "1" or "0" coding where each number represents an alternate response such as "female" or "male" Dummy variables are useful because they enable us to use a single regression equation to represent multiple groups. This means that we don't need to write out separate equation models for each subgroup

What is meant by subclassification of propensity scores?

Propensity score( subclassification groups individuals into subclasses based on their propensity score values. Effect estimates are obtained within each subclass and then combined by weighting by the proportion of observations in each subclass

abstract

Provides a concise summary of the article about 120 words long and tells you the studies hypotheses, methods, and major results.

Institutional Animal care and Use Committee (IACUC)

The AWA mandates that each institution at which animal research takes place must have a local board

Dr. Kang, a cognitive psychologist, conducts an experiment examining the effect of emotion on memory. He provides lists of 15 words to two groups of participants at his university. He puts the names of all the participants in a hat. The first 20 names he assigns to Group A, and the last 20 he assigns to Group B. Group A is given a list of words that are very emotional in content (e.g., passion, murder). Group B is given a list of words that are neutral in content (e.g., houseplant, desk). He then measures how many words each group is able to remember after being distracted for 5 minutes by watching a video about the history of the university. He finds that Group A remembers 15% more words than Group B. Which of the following is the independent variable in Dr. Kang's study?

The emotional or neutral word list

casual inference

The establishment that one variable does cause another, based on covariation, temporal precedence, and the elimination of alternative explanations. - "what causes what"

Tuskeegee 3 ethical violations

The men in the study were harmed, they were not told about treatment for a disease that could have easily cured them, They were subjected to painful and dangerous test; The men were not treated respectfully, they were lied to about the nature of their participation and withheld information from them; The researchers targeted a disadvantaged social group in this study.

Psychologists have established that there is a link between how neat and organize you like to keep your spaces and how well you perform at work. The relationship is such that the neater you keep your space the better you perform at work. A personality researcher wants to test the casual nature of this relationship. He sets up a study where he measures the neatness of a person's work desk and the amount of work they get done in one day. In addition to these variables the researcher also measures how complex the participant's jobs are and how much they talk to the people around them because he thinks these variables may also influence the amount of work a participant gets done in a day. All measurements were taken once in a single sample of 50 workers, and the researcher correlated all his variables after measuring them. 2) If the researcher found a correlation between desk neatness and amount of work completed of r = .71, p = .01 and no other significant correlations what could he conclude?

The neater a participants desk was the more work they got done above and beyond their job complexity and how much they talked to the people around them.

Dr. Kline is especially curious about selective sleep deprivation, where people are kept from entering REM (rapid eye movement) sleep. Using an electroencephalograph (EEG) to monitor brain waves, he plans to let participants sleep until they enter REM sleep and then he will wake them. After the participants are awake for one minute, Dr. Kline plans to let them return to sleep. As they enter REM sleep again, he will wake them again and follow the same procedure. He plans to do this through the entire eight-hour sleep session. The following morning, participants will be asked to take a sample SAT test. Dr. Kline asks his participants to provide informed consent. Doing this is adhering to which principle of the Belmont Report?

The principle of respect for persons

Milgrams ethical violations

The study itself was extremely stressful to the participants "teachers"; The ethical question concerns the lasting effects of the study, the sense that they were capable of harm may have stuck with them for a long time

Psychologists have established that there is a link between how neat and organize you like to keep your spaces and how well you perform at work. The relationship is such that the neater you keep your space the better you perform at work. A personality researcher wants to test the casual nature of this relationship. He sets up a study where he measures the neatness of a person's work desk and the amount of work they get done in one day. In addition to these variables the researcher also measures how complex the participant's jobs are and how much they talk to the people around them because he thinks these variables may also influence the amount of work a participant gets done in a day. All measurements were taken once in a single sample of 50 workers, and the researcher correlated all his variables after measuring them. 1) What problem does this study address with its design?

Third variables

Pearson r correlation

Two continuous variables + Closer to 1.0 the more positive the correlation + closer to -1.0 the more negative the correlation. + A number close to zero shows a weak correlation ex) SAT scores correlated with GPA after 4 years of highschool

Which tailed p value should you use if your hypothesis does not specify which side of the probability distribution the significance would be detected?

Two-tailed

Dichotomous variables

Variables that can take on only two different values - may take on only two values (true or false). Ex) gender.

The mean of the squared deviations of scores from their mean is known as what?

Variance

Researchers were wanting to see if participating in extracurricular activities was linked to depression scores. They sampled a set of students from a local high school and then asked the first set of students to recommend other students to participate in the study. The researchers asked the students if they participated in extracurricular activities and then had them take a test for depressive symptoms. After calculating their results, the researchers claim that participating in an extracurricular activity causes a decrease in depression symptoms. (4) Does the sampling method used in the study result in sample bias?

Yes. Individuals recommended to the study could be similar to those already in the study.

association claim

a claim about 2 variables in which the level of one variable is said to vary systematically with the level of another variable, such that when one variable changes, the other variable tends to change too. (correlated)

casual claim

a claim arguing that a specific change in one variable is responsible for influencing the level of another variable.

frequency claim

a claim that describes a particular rate or level of a single variable

weight of evidence

a conclusion drawn from reviewing scientific literature and considering the proportion of studies that is consistent with a theory.

Spearman rho correlation (rs)

a correlation used for ordinal data + two ranked variables

wait-list control group

a group of randomly selected participants who do not receive a treatment, but expect to and do receive it after treatment of the experimental group(s) ends

zero association

a lack of systematic association between two variables

external validity

a measure how well the results of a study generalize to, or represent, individuals or contexts besides those in the study itself. (Generalize broadly)

construct validity

a measure of how well a variable was measured or manipulated in a study (measure perfectly)

journal

a monthly or quarterly periodical containing peer-reviewed articles on a specific academic discipline or subdiscipline, written for a scholarly audience

confounded

a potential alternative explanation for a research finding

systematic sampling

a probability sampling method in which researchers select members of the population at a regular interval determined in advance. - we might hypothesize that attitudes might differ between groups. - these differences are systematic and not due to bias.

effect size

a quantitative measure of the magnitude of the experimental effect. The larger the effect size the stronger the relationship between two variables small= 0.0 to 0.3 medium= 0.3 to 0.5 large= 0.5 to 1.0

cross-sectional research

a research design that compares groups of people who differ in age but are similar in other important characteristics

conceptual definition

a researchers definition of a variable at an abstract level

probability sample

a sample in which each member of the population has some known chance of being included - a subset of the population selected according to sampling plan in order to obey laws of probability

directionality problem

a situation in which it is unclear which variable in an association came first

theory

a statement, or set of statements, that describes general principles about how variable relate to one another

product moment correlation

a statistic summarizing the strength and direction of linear association between two metric variables + pearson r + z-scores are same distance from mean

factorial design

a study in which there are two or more independent variables, or factors - n levels of the first IV and m levels of the second IV (n x m)

point estimate

a summary statistic from a sample that is just one number used as an estimate of the population parameter

falsifiable

a theory needs to lead to predictions, that, when tested, could prove to be wrong and thus challenge the theory itself

measure variable

a variable in a study whose levels are observed and recorded.

manipulated variable

a variable in an experiment that researchers control by assigning participants to its different levels.

Quasi-experiments are defined by

a. Observations being made before and after the experiment. b. Taking place in more "real-world" environments c. Possibility of biased selection

Longitudinal studies are helpful in answering which types of questions?

a. Questions about change in a person over a long period of time. b. Questions about long-term implications of a medicine. c. Questions about differences in cohorts

variance and standard deviation tell us

about scores are distributed between the extreme scores

If r is a product moment statistic of correlation, r tells us:

about the robustness of the relationship between two variables. The relationship is strong if the relationship between the two variables is consistent across sampling units

parsimonious

all other things being equal, the simples solution is the best

confederate

an actor playing a specific role for the experimenter

positive association

an association in which high levels of one variable go with high levels of the other variable, and low levels of ne variable go with low levels of the other variable.

negative association

an association in which high levels of one variable go with low levels of the other variable.

curvilinear association

an association in which, as one variable increases, the level of the other variable changes its pattern.

variable

an attribute that varies, having at least 2 levels, or values.

cognitive dissonance

an unpleasant state that arises when a person recognizes the inconsistency of his or her actions, attitudes, or beliefs - If a person is induced to do or say something that is contrary to his private opinion, there will be a tendency for him to change his opinion to bring it into correspondence with what he has said or done.

Randomized Experiments

are those in which the sampling units (a.k.a. subjects) are placed in one or another condition based on a process of random assignment.

Co-variation

as one variable changes, the other varies either positively or negatively - ( causation implies correlation but correlation does not imply causation)

negatively skewed distribution

asymmetric distribution in which the majority of the data is concentrated to the right of the mean - The mean will be lower than the median in a negatively skewed distribution.

interval estimate

based on a sample statistic and provides a range of plausible values for the population parameter - a measure of how certain one is in the point estimate.

nonresponse bias

bias introduced to a sample when a large fraction of those sampled fails to respond - an affect on an estimated score due missing responses - This can be estimated *if* information about the non-respondents is also known

justice

calls for a fair balance between the people who participate in research and the people who benefit from it.

continuous variables

can assume an infinite number of values between any two specific values. They are obtained by measuring. They often include fractions and decimals. - may take on infinite number of values (real numbers).

In-depth examinations of an individual, like H.M., are examples of:

case study

Science is most like a

circle

reference list

contains a full bibliographic listing of all of the articles the authors cited in writing their article, acknowledging previous work in the field and enabling interested readers to locate these studies.

history

error due to an uncontrollable event

What is the difference between longitudinal and cross-sectional research?

cross-sectional studies interview a fresh sample of people each time they are carried out, whereas longitudinal studies follow the same sample of people over time.

plagiarism

defined as representing the ideas or words of others as ones own. A form of stealing.

variability of a statistic

described by the spread of its sampling distribution

results

describes the quantitative and, as relevant, qualitative results of the study, including the statistical tests the authors used to analyze the data. Usually provides tables and figures to summarize key results.

implicit theory

describes the specific patterns and biases an individual uses when forming impressions based on a limited amount of initial information about an unfamiliar person

Different conditions

different "levels" of the IV or factor

Significance test (p) =

effect size x size of study

comparison group

enables you to compare what would ahppen both with and without the thing you are interested in

peer-review cycle

ensure that the articles that are published in scientific journals contain novel, well done studies. Rigorously reviewed by other scientists and can be rejected, accepted or accepted with minor or major revisions.

fidelity and responsibility

establish relationships of trust; accept responsibility for professional's behavior

what does range statistics tell us?

extreme scores

null hypothesis significance testing (NHST)

finding the probability (p value) that an observed difference between two means is not due to chance. +a procedure for statistical inference used to decide whether a variable has produced an effect in a study. NHST begins with the assumption that the variable has no effect (see null hypothesis), and probability theory is used to determine the probability that the effect (e.g., a mean difference between conditions) observed in a study would occur simply by error variation ("chance"). If the likelihood of the observed effect is small (see level of significance), assuming the null hypothesis is true, we infer the variable produced a reliable effect (see statistically significant).

pseudoscience

findings disseminated to general public via sources that are not peer reviewed; literally "false science"; its a set of ideas based on theories put forth as scientific when they are not scientific

systematic error

fluctuations in the data that are not due to chance - error that shifts all measurements in a standardized way. Decreases accuracy. Can result in bias

continuous variable example

gpa, age, weight, height

A large effect size might not be statistically significant

if it is not based on very many observations (i.e., the design lack power).

A small effect size can be significant

if there is high-level of power incorporated into the design.

Graphing principle clarity:

if you have a story to tell, make sure that it is easy to understand.

respect of persons

individuals participating in research should be treated as autonomous agents, be free to make up their own minds, and entitled to give informed consent based upon knowledge of risks and benefits of participation.

interval estimate (confidence interval)

interval or range of values within which the true population value is estimated to fall - a measure of how certain one is in the point estimate

Maturation

intrinsic changes to the subjects

good story

is a basic example of thinking the easy way when we accept a conclusion just because it "makes sense"

Insitutional Review board (IRB)

is a committee responsible for ensuring that research on humans is conducted ethically.

The mean score

is a point estimate (PE) of the true score of a population

PsycINFO

is a search engine that the most comprehensive tool for sorting through the vast number of psychological research articles

independent variable

is a variable that is manipulated in an experiment.

hypotheses

is a way of stating the specific outcome that the researcher expects to observe if the theory is accurate

debriefing

is in an interview after the study, the participants are carefully informed about the study's true nature, details, and hypotheses.

random error

is noise in the data as the result of chance fluctuations - error that has equal probability of being too high or too low

empiricism

is the approach of collecting data and using it to develop, support, or challenge, a theory; involves using evidence from our senses or form instruments that assist our senses.

present/present bias

is the tendency to rely only on what is present and ignore what is absent when evaluating the evidence for a conclusion.

dependent variable

is the variable that is measured, or the outcome variable.

translational research

is using knowledge from basic research to develop and test application to healthcare, psychotherapy, or any other intervention

watsons work on little albert ethical violations

it had no clear consent, no attempt made to decondition response, short and long-term consequences considered.

probalisitic

means that inferences are not expected to explain all cases all the ime

refinement

means that researchers must modify experimental procedures and other aspects of animal care to minimize or eliminate animal distress

reduction

means that researchers should adopt experimental designs and procedures that require the fewest animal subjects possible.

replacement

means that researchers should find alternatives to animals in research when necessary.

Correlation coefficients

measure the strength to which different variables are related

method of difference

necessity / control group: If not-X, then not-Y

journalism

new and commentary published or broadcast in the popular media and produced for a general audience

if p value is greater than .05

not significant do not reject null

data falsification

occurs when researchers influence the study's results, perhaps by deleting observations from a data set or by influencing their research subjects to act in the hypothesized way.

data fabrication

occurs when, instead of recording what really happened in a study, researchers invent data that fit their hypotheses.

internal validity aka third-variable rule

on of the 3 rules for establishing causation, referring to the ability to rule out alternative explanations for a proposed casual relationship between 2 variables

covariance

one of 3 rules for establishing causation, stating that the proposed casual variable must vary systematically with changes in the proposed outcome variable

temporal precedence

one of the 3 rules for establishing causation, stating that the proposed casual variable come first in time, before the proposed outcome variable

temporal precedence

one of three criteria for establishing a causal claim, stating that the proposed causal variable comes first in time, before the proposed outcome variable - Y must occur AFTER X

stabile survey

one that has a low degree of variability in the scores of the participants. - stability can be measured or defined by the variance of the scores.

A researcher defines frustration as the number of teeth marks a student makes on a pencil while trying to solve a difficult problem. This is an example of a(n)

operational definition.

within-subjects design

participants are exposed to all levels of the independent variable - Different levels of the independent variable are given to same subjects

consumer of research

people who are interested in reading about research so they can later apply it to their work, hobbies, relationships, or personal growth; needs to properly know different sources and how properly interpret sources/information

Producer of research

people who study things, observe, administer personality questionnaires, and analyze data; may even write up results and present them; needs to be able to properly construct an experiment while also being aware of ethical issues

experimenter expectancy effect

phenomenon in which researchers' hypotheses lead them to unintentionally bias the outcome of a study

Which of the following is NOT necessary for inferring efficient causality?

placebo effect

Which correlation would you use to correlate a continuous variable with a dichotomous variable?

point-biserial

Increasing the sample size of a study is a good way to increase its _____

power

p-value

probability that an observed difference between A and B items is due to chance The probability level which forms basis for deciding if results are statistically significant (not due to chance). **rule of thumb: If p < .05, then you reject the null hypothesis. This is alpha = .05**

Because the creation of the sample is a __________ , one cannot be certain that a sample is an _________

random process; unbiased sample

Quasi-experiments are defined by all of the following except:

random sampling

snowball sampling

recruitment of participants based on word of mouth or referrals from other participants

panel

refers to a set of observation made during a single period of time

type 1 error

rejecting the null hypothesis when it is true (false positive) The significance level determined from a statistical test is the probability of a Type I error

quasi-experimental designs

research designs that employ the logic of experimental methods but lack absolute control over variables - generally have outcome measures, sampling units, and something comparable to a "treatment" condition. However, they do not use random assignment of subjects to groups.

informed consent

research participants right to learn about a research project know its risks and benefits and decide whether to participate

basic research

research whose goal is to enhance the general body of knowledge, without regard for direct application to practical problems

Applied research

research whose goal is to find a solution to a particular real-world problem

beneficence

researchers must take precautions to protect research participants from harm and to ensure participants well being.

deception

researchers withheld some details of the study from participants, and and in some cases they actively lied to them

theory-data cycle

scientists collect data to test, change or update their theories. Theory leads researchers to pose; Research questions which lead to an appropriate; Research Design in the context of the design, researchers formulate; Hypotheses researchers then collect and analyze; Data which feedback into the cycle. Then it either support or revises of the theory.

discussion

section generally summarizes the study's research question and methods and indicates how well the data supported the hypotheses. Discuss the study's significance and may discuss alternative explanations for their data and pose interesting questions raised by the research.

danger of opportunity sample

self-selection, a type of bias that can arise when study participants choose their own treatment conditions, rather than being randomly assigned, especially on-line

data

set of observations

The t-value is a form of

signal-to-noise ratio

if p value is less than .05

significant reject the null hypothesis

Researchers were wanting to see if participating in extracurricular activities was linked to depression scores. They sampled a set of students from a local high school and then asked the first set of students to recommend other students to participate in the study. The researchers asked the students if they participated in extracurricular activities and then had them take a test for depressive symptoms. After calculating their results, the researchers claim that participating in an extracurricular activity causes a decrease in depression symptoms. (3) What type of sampling method did these researchers use?

snowball

Hypothesis

specific, testable prediction about what is expected to happen in a study

What is the difference between variance and standard deviation?

standard deviation is the square root of the variance, variance is the average of all data points within a group.

pop-up principle aka availability heuristic

states that things that easily come to mind tend to guide our thinking.

integrity

strives to be accurate, truthful, and honest in ones role as researcher, teacher, or practitioner.

Method of agreement

sufficiency / experimental group: If X, then Y.

hindsight bias

tendency to exaggerate after learning an outcome, ones ability to have foreseen how something turned out

internal validity

the ability to rule out alternative explanations for a casual relationship between 2 variables (control all extraneous variables)

mean

the average or score

control condition

the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment

Experimental Conditions

the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable

What within-subjects designs are used in single-case experiments?

the conditions are often assigned letters such as the A phase and the B phase, with A being the baseline, or no-treatment phase, and B the experimental, or treatment phase. (Other letters are sometimes used to designate other experimental phases.)

point-biserial correlation

the correlation between a dichotomous and a continuous variable ex) correlation of subjects gender with their performance on the SAT verbal

phi coefficient

the correlation coefficient used when both measured variables are dichotomous and nominal ex) correlation with their gender and their yes or no responses to specific questions

internal validity

the degree to which the effects observed in an experiment are due to the independent variable and not confounds - trustworthy and not influenced by other variables

range

the difference between the highest and lowest scores in a distribution

extended range

the difference between the highest and lowest scores plus 1

The "signal" is

the difference between two means

statistical validity

the extent to which statistical conclusions derived from a study are accurate and reasonable. (leave no room for errors)

external validity

the extent to which the results of a study can be generalized to other situations and to other people

generalizability

the extent to which the subjects in a study represent the populations they are intended to represent; how well the settings in a study represent other settings or contexts

the third variable problem

the fact that a causal relationship between two variables cannot be inferred from the naturally occurring correlation between them because of the ever-present possibility of third-variable correlation

Independent variable (IV)

the factor the researcher manipulates in a controlled experiment (the cause)

cherry picking

the information we take in -seeking and accepting only the evidence that supports what we already think and what we want to think.

An example of a point estimate is:

the mean

Instrumentation

the measurement instrument may change

The larger the sample (N):

the more likely it will be unbiased.

The larger the signal is relative to the noise

the more likely the null hypothesis is not correct

Mode

the most frequently occurring score(s) in a distribution

one-tailed p value

the p value associated with a result supporting a prediction of a specific direction of a research result, for example, Ma > Mb or the sign of r is positive

two tailed p value

the p value associated with a result supporting the prediction of a nonspecific direction for that result

propensity score

the probability of treatment assignment conditional on observed baseline characteristics. - the score allows one to design and analyze an observational (nonrandomized) study so that it mimics some of the particular characteristics of a randomized controlled trial

p tells us

the probability that the observed relationship was due to chance.

Median

the score above and blow which 50% of all scores fall

operational definition

the specific way in which a concept of interest is measured or manipulated as a variable in a study

parapsychology

the study of the evidence for psychological phenomena, such as telepathy, clairvoyance, and psychokinesis, that are inexplicable by science

confirmatory hypotheses testing

the tendency to ask only the questions that will lead to an expected answer

random assignment

the use of a random method to assign participants into different experimental groups

The "noise" is

the variability of the scores within each sample

Benjamin is a social psychologist who studies marriage. He believes that marital satisfaction has two components: the ability to trust one's partner and a belief that one can be a good spouse. His thinking is best described as:

theory

4 scientific cycles

theory- data cycle basic research- applied research cycle Peer-review cycle Journal-to-journalism cycle

what happens if there are multiple independent variables?

they are often displayed in the same graph. Other times different levels of an independent variable are plotted on different graphs

What are the limitations of cross-lagged panel designs?

they do not account for contemporaneous relationships between variables. (Contemporaneous relationships refer to the synchronous correlations between variables within the same time point)

A researcher wants to understand the relationship between graduation rates and geographic locations but is worried that the relationship is influenced by socio-economic status. What is this researcher concerned about?

third-variable problem

what is the goal of counterbalancing?

to ensure internal validity by controlling the potential confounds created by sequence and order effects. (Order is a between-subjects variable)

When are means, medians, and modes used?

to measure central tendency (CT) CT = "what is typical"

What three criteria do scientists use to justify causal inference?

treatment, control, observation

example of dependent variable

two measures of opinion: 1.) Were the tasks enjoyable? Measured on a scale of -5 (extremely dull and boring) to 5 (extremely interesting and enjoyable. 0 was the neutral response. 2.) Would you have any desire to participate in another similar experiment? Measure on a scale of -5 (definitely not) to 5 (definitely so).

The larger the sample (N) is the more likely it will be:

unbiased

standard scores (or z-scores)

units of standard deviations. They tell you how far from the mean score an individual score is.

Discrete variables

values that can be counted (whole numbers) - can take on only a limited number of values (integers). ex) grades

The knowledge that research volunteers tend to be higher in approval need, less authoritarian, and brighter leads researchers to worry about what type of bias?

volunteer bias

The objective of descriptive research is to determine

what's happening?

When would you use a rank-order correlation?

when you want the to know the relationship between two rankings (spearman rho)

If a researcher is only exposing their participants to one level of an independent variable, they are conducting research using a ____ design.

with-in subject

where are independent variables labeled?

x-axis

Type I errors are when ____ while Type II errors are when _____:

you reject the null hypothesis when it is true; you fail to reject the null hypothesis when it is false.

Variance (σ2)

σ^2 = ∑(X-M)^2 / N X = individual scores M = mean score N = the number of scores

How is a confidence interval around a population mean computed?

𝐿𝑜𝑤𝑒𝑟 = 𝑃𝐸 − 2 √ (𝑃𝐸 (1 − 𝑃𝐸) /𝑁) 𝑈𝑝𝑝𝑒𝑟 = 𝑃𝐸 + 2 √ (𝑃𝐸(1 − 𝑃𝐸) /𝑁)