Myers Psychology 8e - Chapter 01

standard deviation

a computed measure of how much scores vary around the mean score. (Myers Psychology 8e p. 042)

scatterplot

a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation). (Also called a scattergram or scatter diagram.) (Myers Psychology 8e p. 031)

correlation

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. The correlation coefficient is the mathematical expression of the relationship, ranging from -1 to 1. (Myers Psychology 8e p. 030)

experiment

a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors. (Myers Psychology 8e p. 036)

random sample

a sample that fairly represents a population because each member has an equal chance of inclusion. (Myers Psychology 8e p. 028)

operational definition

a statement of the procedures (operations) used to define research variables. For example, human intelligence may be operationally defined as what an intelligence test measures. (Myers Psychology 8e p. 025)

statistical significance

a statistical statement of how likely it is that an obtained result occurred by chance. (Myers Psychology 8e p. 043)

survey

a technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them. (Myers Psychology 8e p. 027)

hypothesis

a testable prediction, often implied by a theory. (Myers Psychology 8e p. 025)

population

all the cases in a group, from which samples may be drawn for a study. (Note: Except for national studies, this does not refer to a country's whole population.) (Myers Psychology 8e p. 028)

double-blind procedure

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. (Myers Psychology 8e p. 037)

theory

an explanation using an integrated set of principles that organizes and predicts observations. (Myers Psychology 8e p. 024)

case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles. (Myers Psychology 8e p. 026)

random assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups. (Myers Psychology 8e p. 037)

placebo (pluh-SEE-bo) effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent. (Myers Psychology 8e p. 037)

naturalistic observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation. (Myers Psychology 8e p. 029)

replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances. (Myers Psychology 8e p. 025)

mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores. (Myers Psychology 8e p. 041)

control condition

the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment. (Myers Psychology 8e p. 037)

experimental condition

the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable. (Myers Psychology 8e p. 037)

range

the difference between the highest and lowest scores in a distribution. (Myers Psychology 8e p. 042)

culture

the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next. (Myers Psychology 8e p. 045)

independent variable

the experimental factor that is manipulated; the variable whose effect is being studied. (Myers Psychology 8e p. 038)

median

the middle score in a distribution; half the scores are above it and half are below it. (Myers Psychology 8e p. 041)

mode

the most frequently occurring score(s) in a distribution. (Myers Psychology 8e p. 041)

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independent variable. (Myers Psychology 8e p. 038)

illusory correlation

the perception of a relationship where none exists. (Myers Psychology 8e p. 033)

hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon.) (Myers Psychology 8e p. 020)

false consensus effect

the tendency to overestimate the extent to which others share our beliefs and behaviors. (Myers Psychology 8e p. 028)

critical thinking

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions. (Myers Psychology 8e p. 024)