AP Psychology - Scientific Method, Experimentation, and Research

hypothesis

a testable prediction, often implied by a theory

theory

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

operational definition

a carefully worded statement that specifies how a concept, variable, or term will be measured or observed in a particular study or context

replication

repetition of a research study, usually with different participants in different situations, to determine whether a basic finding can be reproduced

case study

a non-experimental technique in which one individual or group is studied in depth in the hope of revealing universal principles that can generalize a population

naturalistic observation

a non-experimental technique of observing and recording behavior in naturally occurring situations without manipulation or intervention

survey

a non-experimental technique for obtaining the self-reported attitudes or behaviors of a particular group, usually by questioning a random sample

social desirability bias

bias from people reasoning in ways they assume a researcher expects or desires

self-report bias

bias when people report their behavior inaccurately or cannot remember their behaviors

sampling bias

a flawed sampling process that produces a sample that is unrepresentative of a population

random sample

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

population

an entire group of individuals a researcher wants to study or make generalizations about

correlation

a measure of the extent to which two factors vary together, and thus of how well either predicts the other (from -1.00 to 1.00)

correlation coefficient

a statistical index of the relationship between two things

single-blind procedure

an experimental procedure in which the research participants are blind about whether they have received a treatment or a placebo

double-blind procedure

an experimental procedure in which both the research participants and staff are blind about whether the participants received a treatment or a placebo

placebo effect

a phenomenon when a person experiences improvement in a condition after receiving what is believed to be a treatment when in reality the treatment is not chemically active

confounding variable

in an experiment, a factor other than the factor being studied that might influence a study’s results

experimenter bias

bias caused when researchers may unintentionally influence results to confirm their own beliefs

validity

the extent to which a test or experiment measures or predicts what it is supposed to

scientific method

a systematic process of gathering and organizing information through observation and experimentation to answer questions and test ideas objectively

peer reviewers

scientific experts who evaluate a research article’s theory, originality, and accuracy

falsifiability

the possibility that an idea, hypothesis, or theory can be disproven by observation or experimentation

illusory 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 or events to eventually fall back (regress) toward the average