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

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

in an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

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

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

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.

the post-experimental explanation of a study, including its purpose and any deceptions, to its participants

The outcome factor -- the variable that may change in response to manipulations of the independent variable

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

A research method in which an investigator manipulates one or more factors (independent variables) to observe the effects on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant variable

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

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

a testable prediction, often implied by a theory

The perception of a relationship where none exists

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

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

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

The middle score in a distribution--half the scores are above it and half are below it

The most frequently occurring score(s) in a distribution

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

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

A statement of the procedures used to define research variables. Ex human intelligence -- what an intelligence test measures.

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.

all the cases in a group, from which samples may be drawn for a study

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

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

the difference between the highest and lowest scores in a distribution

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

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

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

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

A technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them

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