AP Psych Unit 0 Vocab

Single-blind

Participants do not know whether they are in the experimental or control group

Double-blind

Neither participants nor researchers know group assignments; reduces bias

Normal curve (with percentages of distributions across the curve)

Bell-shaped distribution; ≈68% within 1 SD, 95% within 2, 99.7% within 3 of the mean

Survey technique

Gathering self-reported data via questionnaires or interviews

Cultural norms

Shared rules or expectations for behavior in a group

Confirmation bias

Tendency to favor information that confirms existing beliefs

Hindsight bias

After an outcome, believing you “knew it all along”

Overconfidence

Overestimating the accuracy of one’s knowledge or judgments

Experimental (incl. Random assignment)

Manipulates an IV, randomly assigns participants, measures effect on a DV

Hypothesis

Testable prediction about relationships between variables

Falsifiable

Structured so it could be disproved by evidence

Operational definitions

Exact procedures for measuring or manipulating a variable

Independent variable(s)

Variable(s) manipulated by the researcher

Dependent variable(s)

Outcome variable(s) measured by the researcher

Confounding variables

Uncontrolled factors that may systematically affect the DV with the IV

Sample

Subset of the population studied

Population

Entire group of interest the researcher aims to describe

Representative sample

Sample that mirrors key characteristics of the population

Random sampling

Each member of the population has an equal chance of selection

Convenience sampling

Selecting participants who are easy to access

Sampling bias

Systematic error from a nonrepresentative sample

Generalizability

Extent to which findings apply beyond the study sample/settings

Experimental group

Participants who receive the IV/treatment

Control group

Participants who do not receive the IV; used for comparison

Placebo

Inactive treatment that mimics the real treatment

Social desirability bias

Tendency to give answers that look good to others

Qualitative (i.e., structured interviews)

Collects rich, descriptive, nonnumeric data via structured interviews, etc.

Quantitative (e.g., Likert scales)

Collects numeric data using scales, tests, or surveys

Peer review

Expert evaluation of research before publication

Replication

Repeating a study to verify findings

Variables

Measurable characteristics that can vary (e.g., age, stress)

Directionality problem (correlation)

Uncertainty about which variable influences the other in a correlation

Third variable problem (correlation)

An unmeasured factor may produce the observed correlation

Institutional review

Ethics committee (IRB) review of research to protect participants

Confidentiality

Keeping participants’ data private and secure

Informed consent

Voluntary agreement after being told procedures, risks, and rights

Deception

Withholding/misleading information about a study’s purpose (must be justified and minimal)

Informed assent

Minor’s affirmative agreement to participate with parent/guardian permission

Research confederates

Individuals secretly assisting the researcher within the study

Protection from harm

Safeguarding participants from unreasonable physical or psychological risk

Debriefing

Post

Mean

Arithmetic average of the scores

Median

Middle score when data are ordered

Mode

Most frequently occurring score

Variation

Degree of spread or dispersion in a dataset

Standard deviation

Average distance of scores from the mean

Percentile rank

Percentage of scores at or below a given score

Skewness

Asymmetry of a distribution (tail to left or right)

Regression toward mean

Extreme scores tend to be followed by scores closer to the average

Self-report bias

Inaccuracies in participants’ responses due to memory, misunderstanding, or impression management