Unit 2: Research Methods and Critical Thinking in Psychology

Vocabulary flashcards covering key concepts and terms from Unit 2: Research Methods and Critical Thinking in Psychology.

Hindsight Bias

The tendency to believe, after learning an outcome, that one would have foreseen it; the 'I knew it all along' phenomenon.

Overconfidence

The tendency to think you know more than you actually do.

The Scientific Method

A systematic process for investigating phenomena, testing hypotheses, and drawing conclusions (question, hypothesis, experiment, analysis, conclusion).

Theory

An integrated set of principles that explains and predicts behavior or events.

Hypothesis

A testable prediction derived from a theory.

Operational Definition

A precise statement of how a variable will be measured or defined in a study.

Replication

Repeating a study to see if results hold with different participants or settings.

Case Study

An in-depth description of one person or a small group to reveal universal principles; may have limited generalizability.

Naturalistic Observation

Describing behavior by observing people in their natural environment without manipulation.

Survey

A method of asking many people questions to collect self-reported attitudes or behaviors from a representative sample.

Population

All cases in a group that a researcher wishes to study.

Random Sample

A sample in which every member of the population has an equal chance of being included.

Sampling Bias

A flawed sampling process that produces a non-representative sample.

Descriptive Statistics

Numerical data used to describe characteristics of a sample or population.

Mean

The arithmetic average of a distribution.

Median

The middle score in an ordered distribution.

Mode

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

Range

The difference between the highest and lowest scores.

Standard Deviation

A measure of how much scores vary around the mean.

Histogram

A bar graph depicting a frequency distribution.

Normal Curve / Normal Distribution

A symmetric, bell-shaped distribution; most scores cluster around the mean (68% within 1 SD, ~95% within 2 SDs).

Inferential Statistics

Statistics used to generalize from samples to populations and to test hypotheses.

Statistical Significance

A result unlikely to have occurred by chance, indicating a meaningful difference or effect.

Correlation

A measure of how two variables relate; indicates prediction but not causation.

Correlation Coefficient (r)

A value from -1.0 to +1.0 showing the strength and direction of a linear relationship.

Scatterplot

A graph of paired data; slope shows direction and scatter shows strength of the relationship.

Illusory Correlation

The perception of a relationship when none exists.

Experiment

A study that manipulates an independent variable to observe its effect on a dependent variable, using random assignment to control confounds.

Independent Variable

The experimental factor that is deliberately manipulated.

Dependent Variable

The outcome variable measured in the experiment.

Confounding Variable

An extraneous variable that could influence the dependent variable and blur the results.

Random Assignment

Assigning participants to experimental and control groups by chance to equalize groups.

Experimental Group

The group that receives the treatment or manipulation.

Control Group

The group that does not receive the treatment; serves as a baseline.

Double-Blind Procedure

Neither participants nor researchers know who is in which group to reduce bias.

Placebo Effect

Improvements due to expectations rather than the actual treatment.

Validity

The extent to which a test or experiment measures what it intends to measure.

Informed Consent

Participants are told enough about a study to decide whether to participate.

Debriefing

Post-experiment explanation of the study's purpose and procedures, including any deception used.

IRB (Institutional Review Board)

A panel that reviews research involving humans to protect participants' rights and safety.

Descriptive Statistics vs Inferential Statistics

Descriptive summarizes data; inferential generalizes from sample to population and tests hypotheses.