AP Psych Unit 0 Statistics

Hypothesis

testable predictions

Theory

explains behaviors or events by offering ideas that organize observations

Overconfidence

when one overestimates their abilities or knowledge

Operational Definition

a very precisely worded statement of a research study’s exact procedure, exact definition of variables

Replication

repeating the same procedure with different people in different situations to see if the same conclusion is reached

Case Study

an in-depth analysis of a specific individual or group

Naturalistic Observation

recording the natural behavior of many individuals, used to describe, not explain, behavior

Survey

used to obtain self-reported attitudes or behaviors of a particular group, usually by questioning a random sample

Social Desirability Bias

people responding in ways they believe a researcher wants or wishes them to

Self-Report Bias

people report their behavior incorrectly

Sampling Bias

flawed sampling process that produces an unrepresentative sample

Random Sample

each member of the population has an equal chance of being selected for the sample

Population

the entire group of individuals or objects that share a common characteristic for a study

Correlation

the extent to which two factors vary together, how well they predict each other (not CAUSE each other)

Correlation Coefficient

a statistical measure of how closely two variables are correlated

Single-Blind Procedure

research participants don’t know if they’ve received the treatment or placebo

Double-Blind Procedure

both the research staff and research participants are blind as to whether they received the real or placebo

Placebo Effect

experimental results caused by expectations alone

Confounding/Extreneous Variable

a factor other than the factor being studied that would influence a study’s results

Experimenter Bias

researchers may unintentionally influence results to confirm their own beliefs

Validity

the experiment tests what it’s supposed to

Quantitative Research

relies on quantifiable, numerical data

Qualitative Research

in-depth descriptive data that is not reported numerically

Informed Consent

giving potential participants enough information about a study to enable them to choose if they want to participate

Debriefing

explaining the purpose and deceptions of the experiment after participationMod

Mode

the most frequently occurring value in a data set

Mean

the average of all values in a data set

Median

the middle number in a data set

Standard Deviation

a statistical calculation of how much failures in a data set vary from the mean

Normal Curve

a symmetrical data distribution where 50% of the data falls above the mean and 50% falls below

Meta-Analysis

analyzing the results of multiple studies to reach an overall conclusion

Statistical Significance

how likely it is that differences in results are a result of random chance (significant = occurred by more than chance, not significant = due to chance)