AP Psychology Test Review

Hindsight bias

Tendency to believe after learning an outcome that you could have predicted it.

Theory

explains behaviors or events by offering ideas that organize observations.

Hypothesis

a testable prediction based on your theory or what will happen in your study

Operational definition

explains exactly how you will measure and manipulate variables

Replication

sharing your research for other people to do to test your results

Case study

an in-depth examination of one person or small group

Naturalistic observation

watching and recording behavior as it naturally occurs

Survey

collect information through questionnaires or interviews

Sampling bias

a flawed sampling process that produces an unrepresentative sample.

Population

all the cases in a group, from which samples may be drawn for a study

Random sample

every person in the population has an equal chance of being chosen

Correlation

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

Correlation coefficient

a number that shows the strength and direction of a relationship

Variable

anything that can vary and is feasible and ethical to measure.

Scatter plot

display the relationship between two variables using dots

Illusionary correlation

perceiving a relationship where none exists, or perceiving a stronger-than-actual relationship.

Regression toward the mean

the tendency for extreme or unusual scores to fall back (regress) toward the average

Experiment

manipulates an independent variable to see its effect on a dependent variable

Experimental group

receives the independent variable being tested

Control group

does not receive the independent variable

Random assignment

places participants randomly into either group to reduce bias

Double-blind procedure

neither participants nor researchers know who received the treatment

Placebo effect

a psychological and physiological phenomenon where a person's symptoms improve after receiving a fake or inactive treatment

Independent variable

what the researcher changes or manipulates

Confounding variables

other factors that could influence your results if not controlled

Dependent variable

what the researcher measures as the outcome

Validity

the experiment will test what it is supposed to test.

Informed consent

professional explains a treatment, its risks, benefits, and alternatives so a person can freely agree or say no

Debriefing

an ethical procedure used after a research study, and a crisis intervention used after a traumatic event

Descriptive Statistics

summarize a single data set you have collected.

Histogram

a bar graph depicting a frequency distribution

Mode

the number that appears most frequently in the data set

Mean

the average of all numbers added together and divided by how many numbers

Median

the middle number when data is arranged in order

Skewed distribution

a representation of scores that lack symmetry around their average value.

Range

the distance between the highest and lowest scores in your data

Standard deviation

measures how far data points are from the mean

Normal curve/distribution

shows data plotted on a graph with a peak in the center

Inferential statistics

make predictions about a larger population

Statistical significance

tells you if a result is likely real or just due to chance

Which demonstrates the need for psychological science?

Our commonsense thinking about human thoughts and behaviors is not always accurate.