Unit 1 Vocab | AP Psychology

Correlation Coefficient

Correlation Coefficient

a statistical index of the relationship between two things (from -1.00 to +1.00)

Random Sample

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

Dependent Variable

In an experiment, the outcome that is measured; the variable that may change when the independent variable is manipulated

Double-Blind Procedure Experiment

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies

Introspection

the process of looking inward in an attempt to directly observe one's own psychological processes

Naturalistic Observation

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

Independent Variable

in an experiment, the factor that is manipulated; the variable whose effect is being studied

Range

the difference between the highest and lowest scores in a distribution

Descriptive Statistics

numerical data used to measure and describe characteristics of groups; includes measures of central tendency and measures of variation

Illusory Correlation

perceiving a relationship where non exists, or perceiving a stronger-than-actual relationship

Inferential Statistics

numerical data that allow one to generalize- to infer from sample data the probability of something being true of a population

Mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores

Normal Curve

(normal distribution) a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (about 68 percent fall within one standard deviation of it) and fewer near the extremes

Operational Definitions

a carefully worded statement of the exact procedures (operations) used in research study. For example, human intelligence may be operationally defined as what an intelligence test measures

Random Assignment

assigning participants by experimental and control groups by chance, thus minimizing preexisting differences between the different groups

Psychology

the science of behavior and mental processes

Confounding Variable

a factor other than the factor being studied that might influence a study's results

Placebo Effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent

Case Study

a descriptive technique in which one individual or group is studied in depth in hopes of revealing universal principles

Experimental Group

in an experiment, the group exposed to the treatment, that is, to one version of the independent variable

Median

the middle score in a distribution, obtained by adding the scores and then dividing by the number of scores

Mode

the most frequently occurring score(s) in a distribution

Population

all those in a group being studied, from which samples may be drawn (Note: except for national studies, this does not refer to a country's whole population)