AP Psychology: Experiments & Research Methods

causation

A cause and effect relationship in which one variable controls the changes in another variable.

correlation

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

survey

a method that asks a particular group of people to report their attitudes or behaviors in a question format

curiosity

a passion to explore and understand without misleading others or being misled

placebo effect

a response to the belief that the independent variable will have an effect, rather than the actual effect of the independent variable (which can be the confounding variable)

random sample

a sample that represents a population so that each member has an equal chance of inclusion

scientific method

a set of general procedures for gathering and analyzing data, and that can be repeated by other researchers

operational definitions

a statement of the procedures used to define research variables

correlation coefficient

a statistical measure of the relationship between two things

statistical significance

a statistical statement of how likely it is that an obtained result occurred by chance

hypothesis

a testable prediction, often implied by a theory

population

all cases in a group study from which samples can be drawn

humility

an awareness of our own vulnerability to error and an openness to surprises and new perspectives

theory

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

case study

an observation technique that uses an in depth study of an individual to see if it can reveal universal principles

curious skepticism

asking question "what do you mean" and "how do you know"

random assignment

assigning participants to experimental and control groups by chance, minimizing pre-existing differences between groups

scientific attitude

being skeptical but not cynical, open but not gullible

demand characteristics

clues participants discover about the purposes of the study that suggest how they should respond/act

placebo effect

experimental results caused by expectations alone

confounding variables

factors that cause differences between the experimental group and the control group (besides the independent variable)

variation

how similar or diverse the scores are

empirical approach

letting the facts speak for themselves

effect size

magnitude and reliability

single-blind procedure

patients don't know which group is the control and which group is the experimental

replicate

repeating the essence of a research study to see whether the basic finding extends to other people

random sampling

representative sample of cases

inferential statistics

statistics that are used to interpret data and draw conclusions

overconfidence

tendency for people to think that they know more than they actually do

dependent variable

the behavioral or mental processes that are measured in an experiment (the effect)

control group

the comparison group, the group of the sample that contains the presence of the independent variable

independent variable

the factor the researcher manipulates (the cause)

experimental group

the group of the sample that receives the treatment or the independent variable

double-blind procedure

the patients and the researchers do not know which group is the control and which is the experimental

percentile score

the percentage of scores at or below a particular score

illusory correlation

the perception of a correlation where none exists

wording effects

the phrasing of a question that may affect how people express their opinions

variability

the spread or dispersion of a set of research data or distribution

naturalistic observation

the technique of observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

critical thinking

thinking that examines assumptions, discerns hidden values, evaluates evidence and assesses conclusions

positive correlation

two sets of scores that tend to rise or fall together (positive slope)

negative correlation

two sets of scores that vary inversely (negative slope)