AP Psych Unit 0

Validity

Accuracy of a measure in research.

Double-blind

Neither participants nor researchers know group assignments.

Placebo

Inactive substance used for comparison in experiments.

Hindsight bias

Belief that past events were predictable.

Mean

Average value calculated by summing data.

Mode

Most frequently occurring value in data.

Median

Middle value when data is ordered.

Range

Difference between highest and lowest values.

Standard deviation

Measure of data dispersion around the mean.

Experimental group

Group receiving treatment in an experiment.

Control group

Group not receiving treatment for comparison.

Independent variable (IV)

Variable manipulated to observe effects.

Dependent variable (DV)

Variable measured in response to IV changes.

Confounding variable

Third variable affecting IV and DV relationship.

Random sampling

Selecting participants randomly from a population.

Random assignment

Randomly assigning participants to different groups.

Statistical significance

Results unlikely due to chance alone.

Ethical guidelines

Standards ensuring research integrity and participant safety.

Causation vs. correlation

Causation implies direct influence; correlation does not.

Correlation coefficient

Numerical value indicating strength of relationship.

Illusory correlation

Perception of a relationship that doesn't exist.

Normal curve

Bell-shaped distribution representing data variability.