AP Psych Unit 0: Science Practices

• Hindsight Bias – Believing you "knew it all along."

• Confirmation Bias – Seeking info that supports beliefs.

• Overconfidence – Thinking you're more accurate than reality.

Scientific Method Terms (Topic 0.3)

• Peer Reviewers – Experts who evaluate scientific work.

• Theory – Explanation based on evidence.

• Hypothesis – Testable prediction based on theory.

• Falsifiable – Can be proven false by evidence.

• Operational Definition – Describes variables in measurable terms.

• Replication – Repeating study for consistent results.

Research Methods (Topic 0.3)

• Case Study – In-depth study of one subject.

• Meta-Analysis – Combines results of many studies.

• Naturalistic Observation – Watching behavior in natural setting.

• Survey – Questionnaire to gather self-reported data.

• Social Desirability Bias – Giving socially approved answers.

• Self-Report Bias – Inaccurate personal reporting.

• Experimenter Bias – Researcher influences outcome unintentionally.

Sampling Terms (Topic 0.3)

• Population – Entire group being studied.

• Sample – Subset of population studied.

• Sampling Bias – Sample doesn’t represent population.

• Random Sample – Everyone has equal selection chance.

• Convenience Sampling – Sample easiest to reach.

• Representative Sample – Accurately reflects population characteristics.

Research Design (Topic 0.4)

• Experimental Methodology – Manipulates variables to find cause.

• Non-Experimental Methodology – Observes without changing variables.

• Correlation – Relationship between two variables.

• Correlation Coefficient – Strength/direction of correlation.

• Variable – Anything measurable or changeable.

• Scatterplot – Graph showing variable relationships.

• Illusory Correlation – Perceiving relationship where none exists.

• Directionality Problem – Can’t tell which variable influences the other.

• Third Variable Problem – Unmeasured variable causes both.

• Regression Toward the Mean – Extreme scores move toward average.

Experimental Design (Topic 0.4)

• Experiment – Controlled test of variables.

• Experimental Group – Gets treatment or condition.

• Control Group – No treatment; comparison group.

• Independent Variable – Manipulated by researcher.

• Dependent Variable – Measured outcome.

• Random Assignment – Subjects randomly in groups.

• Single-Blind Procedure – Participants unaware of group.

• Double-Blind Procedure – Both participants/researchers unaware.

• Placebo – Inactive substance used in control.

• Placebo Effect – Response to fake treatment.

• Confounding Variable – Affects DV besides IV.

• Validity – Measures what it claims to measure.

Ethics in Research (Topic 0.5)

• Quantitative Research – Uses numbers/statistics.

• Qualitative Research – Uses open-ended, descriptive data.

• Likert Scales – Rating scales for opinions.

• Institutional Review – Approves ethical research.

• Informed Consent – Participant agrees after knowing risks.

• Informed Assent – Minor’s agreement to participate.

• Protect from Harm – No unnecessary physical/psychological harm.

• Confidentiality – Personal data kept private.

• Research Confederates – Actors in an experiment.

• Debriefing – Explaining study afterward.

Statistics (Topic 0.6)

Descriptive Statistics

• Histogram – Bar graph of data distribution.

• Measure of Central Tendency – Shows center of data.

  • Mode – Most frequent score.

  • Mean – Average score.

  • Median – Middle score.

• Percentile Rank – Score’s position in distribution.

• Skewed Distribution – Scores distorted left or right.

• Bimodal Distribution – Two frequent scores (peaks).

Measures of Variation

• Range – Difference between highest and lowest.

• Standard Deviation – Spread of scores around mean.

• Normal Curve – Bell-shaped symmetrical distribution.

Inferential Statistics

• Inferential Statistics – Draw conclusions about population.

• Meta-Analysis – Repeated here—study of studies.

• Statistical Significance – Unlikely result due to chance.

• Effect Size – Strength of experimental outcome.