Meyers Unit 2

Correlation

A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

survey

A technique for ascertaining the self reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of graph

Hypothesis

A testable prediction, often implied by a theory

experimental group

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

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

standard deviation

a computed measure of how much scores vary around the mean score

confounding variable

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

Scatterplot

a graphed cluster of dots, each of which represents the values of two variables

random sample

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

operational definition

a statement of the procedures used to define research variables

correlation coefficient

a statistical index of the relationship between two things (from -1 to +1)

statistical significance

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

Population

all the cases in a group being studied, from which samples may be drawn

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

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

case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles

random assignment

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

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

Natural Observation

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

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

mean

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

range

the difference between the highest and lowest scores in a distribution

illusory correlation

the perception of a relationship where none exists

hindsight bias

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