Exam 9: Basic Between-Subjects Designs

Two Independent Groups A "no-treatment" condition in an experiment, which measures how subjects ordinarily perform on the dependent measure, is called the

Selecting and Recruiting Subjects Small samples are adequate when

Two Independent Groups Brady's (1958) study of ulcers in monkeys compared "executive monkeys" who could prevent shock by hitting a button at least once every 20 seconds and "nonexecutive monkeys" who had no control over the shocks and received the same number of shocks as the executive monkeys to which they were yoked.Which design did Brady use?

Selecting and Recruiting Subjects When the independent variable creates larger group differences on the dependent variable than we would see if we randomly assigned subjects to groups and only measured them, this demonstrates

Multiple Groups An experimenter can use a ____ to determine the appropriate levels of an independent variable before conducting the actual experiment.

Selecting and Recruiting Subjects You may require ____ subjects per condition to detect a weak treatment effect.

Selecting and Recruiting Subjects A researcher should ____ to estimate the minimum number of subjects needed for each treatment group.

Selecting and Recruiting Subjects As a rule of thumb, you should assign at least ___ subjects to each treatment group.

Introduction Ashton studied the effect of wearing single-strap and double-strap backpacks on shoulder muscle contraction.He tested the same subjects in both single-strap and double-strap conditions to control individual differences in trapezius muscle activity.This study employed a ____ design.

Two Matched Groups Dexter formed matched pairs when systolic blood pressures fell within 5 mm Hg.Which form of matching did he use?

Introduction All of these are specified by an experimental design except

Multiple Groups Lassen (1973) randomly assigned patients to sit 3, 6, or 9 feet away from a therapist and then had raters judge the patients' anxiety.Which design did she use?

Introduction Carlie randomly assigned subjects to either walk 30 minutes a day/three times a week or 45 minutes a day/two times a week and then measured their resting heart rates at the end of two months.Which design was this?

Selecting and Recruiting Subjects If we anticipate large individual differences in subject performance on the dependent variable, we should

Selecting and Recruiting Subjects A sample's representativeness affects

Selecting and Recruiting Subjects Since Andrew only had 3 days to collect experimental data, he obtained a convenience sample of students eating lunch in the cafeteria.Nonprobability sampling worried him because of risk to his experiment's

Two Matched Groups Researchers will always create treatment groups of equal size if they use ____ to randomly assign subjects to treatment conditions.

Introduction What does "between" subjects mean in a between-subjects experiment?

Two Independent Groups Weiss (1972) criticized Brady's (1958) "executive monkey" study for its

Two Matched Groups In a two matched groups design, the matching variable should be highly correlated with the ____ variable.