AP Psych Unit 0: Research Methods

Cultural norms

The shared expectations and rules that guide behavior within a specific society.

Confirmation bias

A tendency to search for information that supports our preconceptions and to ignore contradictory evidence

Hindsight bias

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

Overconfidence

The tendency to be more confident than correct, overestimating the accuracy of beliefs and judgments.

Independent variables

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

Confounding variables

A factor other than the factor being studied that might influence a study's results.

Dependent variables

The outcome that is measured in an experiment.

Random assignment

Each participant has an equal chance of being placed into the control or experimental groups.

Case study

One individual or group is studied in depth in the hope of revealing universal principles.

Correlation

A measure of the relationship between two variables that does not prove causation.

Positive correlation

A correlation where as one variable increases, the other also increases.

Negative correlation

The relationship between two variables in which one variable increases as the other decreases.

Meta-analysis

A procedure for statistically combining the results of many different research studies.

Naturalistic observation

Observing and recording behavior in naturally occurring situations without manipulation.

Hypothesis

A proposed explanation made on the basis of limited evidence as a starting point for investigation.

Falsifiable hypothesis

Predictions that can be clearly shown to be untrue with some observation.

Operational definition

a detailed description that defines a variable to such a degree that everyone collects data in the same way. It must be measurable.These help facilitate replication of a research study.

Replication

Repeating a research study to see whether the basic finding can be reproduced.

Central tendency

A measure that represents the typical response or behavior of a group.

Variation

A measure used to describe the distribution of data.

Percentile rank

Percentage of scores falling at or below a specific score.

Mean

The arithmetic average of a distribution, obtained by adding scores and dividing by their number.

Median

The middle score in a distribution; half the scores are above and half are below it.

Mode

The most frequently occurring score(s) in a distribution.

Range

The difference between the highest and lowest scores in a distribution.

Normal curve

The symmetrical bell-shaped curve describing the distribution of many attributes.

Wechsler Adult Intelligence Scale (WAIS)

The most widely used intelligence test today with a mean of 100 and standard deviation of 15.

Positively-skewed distribution

A distribution in which scores pile up at the low end, skewing the mean higher.

Negatively-skewed distribution

A distribution in which scores pile up at the high end, skewing the mean lower.

Bimodal distribution

A frequency distribution with two modes, appearing as two distinct peaks.

Standard deviation

A measure of variability describing the average distance of each score from the mean.

Regression toward the mean

The tendency for extreme scores to fall back toward the average with repeated testing.

Sample

A subset of the population.

Population

The group being studied.

Representative sample

A sample that fairly reflects the characteristics of a population.

Random sampling

A technique where every member of the population has an equal chance of being selected.

Convenience sampling

A method of collecting samples that are easily located, which limits generalizing the results.

Generalizing

The ability to apply research findings to larger segments of society.

Experimental group

The group exposed to the treatment in an experiment.

Control group

The group that is not exposed to the treatment in an experiment.

Placebo

An inert substance used in experiments.

Placebo effect

The phenomenon where participant expectations influence their behavior.

Single-blind study

Only the researcher knows which group the participant is assigned to.

Double-blind study

Neither the researcher nor the participant knows which group the participant is in.

Experimenter bias

When a researcher's expectations influence the results of a study.

Social desirability bias

The tendency of respondents to answer questions favorably so they are looked favorably upon by researcher

Qualitative research

Research aimed at gathering and analyzing non-numerical data to understand social reality.

Structured interviews

Interviews where all applicants are asked the same set of standardized questions.

Self-report bias

Systematic errors that occur in self-report data.

Wording effects

How subtle changes in wording can affect survey results.

Quantitative research

Research that provides data expressed with numbers.

Likert scales

A rating scale used to measure participants' opinions and attitudes.

Peer review

A process of evaluating an author's work by experts in the same field.

Scatterplot

A graph that shows the values of two variables, indicating a correlation

Correlation coefficient

A statistical measure of how well two factors vary together.

Effect sizes

A value measuring the strength of the relationship between two variables.

Statistical significance

A statement of how likely it is that an obtained result occurred by chance.

P value

The probability of results being attributed to chance.

Directionality problem

A problem in correlational studies where causation cannot be determined.

Third-variable problem

A problem in correlational studies where a relationship is caused by an unidentified factor.

Institutional review

Groups that evaluate risks and benefits of research involving human participants.

Informed consent

An ethical principle that participants be informed to choose whether to participate.

Informed assent

Participant's agreement to participate without full understanding.

Protection from harm

An ethical requirement to protect research participants from harm.

Confidentiality

An ethical requirement to hold information in confidence.

Deception

Misleading or hiding the truth from study participants, requiring justification.

Debriefing

Providing a post-experimental explanation of a study to its participants.

Non-experimental methodology

Research that measures variables without manipulation.

Experimental methodology

Research involving the manipulation of factors to observe effects.

Confederates

Research actors who participate secretly alongside actual subjects.

Illusory correlation

The perception of a relationship where none exists.