G&g: Chapter 7: Experimental Design I: Single-Factor Designs

Single-factor designs have one independent variable.

A single-factor, between-subjects design where the independent variable is manipulated and random assignment is used to create equivalent groups.

A single-factor, between-subjects design where the independent variable is manipulated and a matching procedure followed by random assignment is used.

A between-subjects design where the independent variable is a subject variable, and therefore the subjects in a study are placed into the groups "after the fact" of their already existing subject characteristics. Also known as quasi-experiment.

A single-factor, within-subjects design (that is, each participant in the study experiences each level of the independent variable).

A single-factor, between-subjects design where the independent variable is a subject variable, and therefore the subjects in a study are placed into the groups "after the fact" of their already existing subject characteristics. Also known as quasi-experiment.

A single-factor, within-subjects design.

The coding results of two or more observers of a study is in consensus.

The variability of each set of scores being compared ought to be similar.

A t test for comparing two sets of scores used when the two groups of participants are completely independent of each other.

A t test comparing two sets of scores used when the independent variable is a within-subjects factor, or if two groups of people are formed in such a way that some relationship exists between them.

A single-factor design using three or more levels.

A variable for which a number of intermediate values exist ; in other words, the variable exists on a continuum.

A variable in which each level represents a distinct category and no intermediate points can occur.

Line graph preferred; bar graph acceptable.

Line graph preferred; bar graph acceptable.

Use a bar graph; a line graph is inappropriate.

(Analysis of Variance) the one in the "one-way" means one independent variable. In essence, a one-way ANOVA tests for the presence of an overall significant effect that could exist somewhere between the levels of the independent variable.

Equal to a t test, the F score/ratio examines the extent to which the obtained mean differences could be due to chance or are the result of some other factor. (An ANOVA yields this score/ratio).

An ANOVA source table summarizes the analysis by indicating the sums of squares (SS), degrees of freedom (df), and mean square (MS) for each source of variance, and a final F ratio, which determines if differences found among the groups are statistically significant or due to chance.

From Latin, meaning "I shall please". A substance given to a participant in a form suggesting specific pharmacological effect when, in fact, the substance is pharmacologically inactive.

Often used in research designed to assess the effectiveness of a program or in studies on the effects of psychotherapy.

Used when each subject in the experimental group, for one reason or another, participates for varying amounts of time or is subjected to different types of events in the study. Each member of the control group is then matched, or "yoked", to a member of the experimental group so that, for the groups as a whole, the time spent participating or the types of events encountered is kept constant.