AP Psychology Modules 4-7

Survey

conducting a study in less depth

Placebo effect

experimental results caused by expectations alone

Statistical significance

how likely it is that an obtained result occurred by chance

skewed

lopsided, lacks symmetry around the average value

Inferential statistics

numerical data that allow one to infer from sample data the probability of something being true

Descriptive statistics

numerical data used to measure and describe characteristics of groups (includes central tendency and variation)

Naturalistic observation

observing and recording behavior in naturally occurring situations without manipulation

Illusory correlation

perceived but nonexistent correlation

Experiment

process of manipulating and controlling some variables to come up with conclusions

Replication

repeating the same things in a research study, with different people in different situations

Confounding variable

something other than the independent variable that might produce an effect in an experiment

Correlation coefficient

statistical measure that shows how closely two things vary together

Hindsight bias

the tendency to believe that, after an outcome, one would have foreseen it

Critical thinking

thinking that doesn't blindly accept arguments and conclusions

Independent variable

variable that is manipulated

Dependent variable

variable that may change because of the independent variable

Histogram

a bar graph depicting a frequency distributions

Operational definition

a carefully worded statement of the operations used in a study

Case study

a descriptive technique where a person is studied in depth reveal universal principles

Sampling bias

a flawed sampling process that produces an unrepresentative sample

Scatterplot

a graphed cluster of dots, each representing the values of two things

Correlation

a measure of how two variables change together

Random sample

a sample that fairly represents a population because each person has an equal chance of participating

Hypothesis

a testable prediction

Population

all the people in a group being studied

Validity

an experiment will test what it is supposed to test

Theory

an explanation using an integrated set of principles that organizes observations and predicts behaviors or events

Random assignment

assigning people to experimental and control groups by chance