AP Psychology: Research Unit

A high standard deviation indicates

inconsistent results, large range, less reliable findings

A low standard deviation indicates

consistent results, small range

achievement tests

tests that measure a person's existing knowledge and skills

American Psychological Association (APA)

professional organization representing psychologists in the United States, publishes ethical guidelines in psychological research

Animal Research Ethics: Acquiring Animals

must be acquired for research in a legal and humane manner

Animal Research Ethics: Care

researchers must care for the animals and provide humane housing

Animal Research Ethics: Purpose

there must be a clear scientific purpose, species must be chosen because they're best suited to answer scientific questions

Animal Research Ethics: Suffering

experiments must be designed in a way allowing for least amount of suffering possible

Animal Research Ethics: Supervision

a trained psychologist must supervise

aptitude tests

tests that assess how well a person can learn or acquire skills and abilities

Belmont Report (1979)

summarizes the basic ethical principles and guidelines for the protection of human subjects of research. (Respect for persons, beneficence and justice)

bimodal distribution

a frequency distribution having two different values that are heavily populated with cases

Case studies

involve up-close, in-depth, & detailed examination of a subject in hopes of generalizing. May use personal interviews, direct observation, and psychometric tests. Ex: Phineas Gage: Rod went through his temporal lobes, causing a drastic personality change. Patient HM: Removed hippocampus caused loss of short-term memory

Strengths: generalize from one to many situations, can help avoid some ethical concerns

Weaknesses: one case can be misleading, anecdotal evidence, persuades people more easily (the availability heuristic)

Confederates

in psychological and social research, a confederate is a person who is working with the experimenter and posing as a part of the experiment, but the subjects are not aware of this affiliation

Confidentiality

Participants and the data gained from them must be kept anonymous unless they give full consent, no legal obligation to disclose criminal acts

confounding variable

a factor other than the factor being studied that might influence a study's results (a good, accurate study will have little to none)

construct validity

The extent to which there is evidence that a test measures a particular hypothetical construct.

content validity

The degree to which the content of a test is representative of the domain it's supposed to cover.

control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Control Variables (constants)

all of the factors that are the same in both the experimental group and the control group

correlation coefficient

A numerical index of the degree of relationship between two variables, values between -1 and 1 with - being - correlation, + being + correlation, and 0 being no correlation. the closer to -1 or 1, the stronger the correlation.

Correlational study

seeing if there's a relationship between two variables. use surveys to obtain information on 2 factors, plot data on a scatterplot, and determine the correlation

strength: shows a relationship

weakness: correlation doesn't equal causation

criterion validity

the extent to which a measure is related to an outcome

cross-sectional study

a study in which people of different ages are compared with one another

debrief

post-experimental explanation of a study, including its purpose and any deceptions, to its participants

deception

misleading participants about the true purpose of a study or the events that will actually transpire, must be avoided or minimized

Dependent Variable (DV)

the research variable that is influenced by the independent variable, and the impact can be measured

Descriptive research methods

describe a person, group, or population, their weakness is that they can't demonstrate causation

descriptive statistics

numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.

directionality problem

a problem encountered in correlational studies; the researchers find a relationship between two variables, but they cannot determine which variable may have caused changes in the other variable

double-blind study

study in which neither the experimenter nor the subjects know if the subjects are in the experimental or control group

effect size

a measure of the strength of the relationship between two variables or the extent of an experimental effect

Ethics

the correct rules of conduct necessary when carrying out research, to protect participants, psych's reputation, and psychologists

Experiment

prove cause and effect, see if changing one variable can effect another variable

experimental group

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable.

experimental methodology

type of research method where the researcher manipulates one variable (independent variable) to determine its effect on another variable (dependent variable)

experimenter bias

a phenomenon that occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained

falsifiable

able to be disproven by experimental results

Flynn effect

observation that each generation has a significantly higher IQ than the previous generation

Generalizability

the extent to which we can claim our findings inform us about a group larger than the one we studied

Hawthorne effect

A change in a subject's behavior caused simply by the awareness of being studied

hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it

Hypothesis

A testable prediction, often implied by a theory, that will be tested in the experiment

illusory correlation

perception of a relationship where none exists, or perception of a stronger relationship than actually exists

Independent Variable (IV)

The experimental factor that is manipulated; the variable whose effect is being studied.

inferential statistics

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

informed consent

pre-experimental, an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

Institutional Review Boards (IRBs)

groups of people responsible for reviewing proposed research to ensure that it meets the accepted standards of science and provides for the physical and emotional well-being of research participants

Likert Scale

a numerical scale used to assess attitudes; includes a set of possible answers with labeled anchors on each extreme

Longitudinal studies

studying the same group of individuals over an extended time, often related to childhood development Ex: Three identical strangers

Mean

the arithmetic AVERAGE of a distribution, obtained by adding the scores and then dividing by the number of scores, impacted by outliers

Median

the MIDDLE score in a rank-ordered distribution; half the scores are above it and half are below it

median & mode are above mean

negatively skewed

median & mode are below mean

positively skewed

Meta-analyses

a statistical method that combines the results of multiple scientific studies to draw overall conclusions, usually widely accepted and accurate ones

Mode

the MOST frequently occurring score(s) in a distribution

Naturalistic observation

researches observe subjects in their natural environment, used when lab research is too unrealistic, costly, or would likely influence subjects' behavior. Ideally, the subject needs to be made aware. Ex: "What would you do?" With John Quiñones, nature documentaries, and Jane Goodall's work with chimpanzees

Strengths: opportunity to see authentic behaviors and study things that can't be manipulated in a lab (ethics!)

Weaknesses: can't determine cause and effect, cannot control outside/confounding variables, and researchers can't interfere

negative correlation

the relationship between two variables in which one variable increases as the other variable decreases, opposite directions

negatively skewed

one/few extremely low scores- mean, median, mode

non-experimental methodology

research that lacks the manipulation of an independent variable

null hypothesis

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

operational definition

a carefully worded statement of the exact procedures used in a research study, must be specific & measurable

p-value

the percentage probability that the results are due to chance, usually set at 5%, meaning that if p is greater than or equal to 0.05, the results are usually significant

peer reviewers

scientific experts who evaluate a research article's theory, originality, and accuracy

percentile rank

Percentage of scores falling at or below a specific score.

Placebo

in drug experiments, given to control groups, a fake pill or procedure that has no therapeutic effect

placebo effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

Population

the largest collection of people that are of interest to the researcher (referred to as N)

positive correlation

as one variable increases, the other also increases, or as one decreases so does the other. Both variables move in the same direction.

positively skewed

one/few extremely high scores- mode, median, mean

predictive tests

tests that attempt to measure what will happen based on the data collected (EX. SAT has a strong positive correlation between success in college)

predictive validity

The success with which a test predicts the behavior it is designed to predict; it is assessed by computing the correlation between test scores and the criterion behavior.

Protection of participants

Participants should be protected from physical or mental health, including stress - risk of harm must be no greater than that to which they are exposed in everyday life

qualitative data

descriptive data

quantitative data

numerical data

random assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

random sampling

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

range

the difference between the highest and lowest scores in a distribution

regression toward the mean

the tendency for extreme or unusual scores to fall back (regress) toward their average.

Reliability

the extent to which a test yields consistent results, as assessed by the consistency of scores on two halves of the test, on alternate forms of the test, or on retesting

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances and validating the findings

Sample

A (representative) subset of a population, examined in hopes of learning about the population (referred to as n)

sampling error

an error that occurs when a sample somehow does not represent the target population

self-fulfilling prophecy

an expectation that causes you to act in ways that make that expectation come true

self-report bias

systematic errors that can occur in self-report data because participants are unable or unwilling to answer accurately

single-blind study

study in which the subjects do not know if they are in the experimental or the control group

Social disirability bias

occurs when survey respondents are not honest because they don't want to be viewed negatively by the person conducting the interview

split-half reliability

A measure of reliability in which a test is split into two parts and an individual's scores on both halves are compared.

standard deviation

a measure of variability that describes an average distance of every score from the mean

standardization

defining uniform testing procedures and meaningful scores by comparison with the performance of a pretested group

statistical significance

how likely it is that an obtained result occurred by chance, often examined in terms of p-value, significant when p is less than or equal to 0.05

stereotype lift

awareness of positive expectations can actually improve performance on tasks

stereotype threat

apprehension about confirming negative stereotypes related to one's own group

Surveys

typically a list of questions answered by research subjects/participants Ex: Gallup polls