Exam 3: Research Design: the Experimental Model and Its Variations

Pre-experimental designs lack any equivalence of groups and include one- and two-group ex post facto and one-group before-after designs.

The two-group ex post facto design,is an example of a longitudinal design.

Experimental group is the group that is exposed to stimuli or experimental arrangements.

Discuss the Provo and Silverlake experiments.

Classic experimental design refers to the attempt to select and assign subjects to experimental and control groups in such a manner that they are as similar as possible.

__________ is a combination of errors introduced by selection bias plus the differential maturation of groups.

__________ are intended to manage or control the problem of multiple-treatment inference,in which X1 refers to one treatment,X2 a second,X3 a third,and X4 a fourth.

The Solomon four-group design Solomon,1949)is viewed by some as the purest of research designs.

Quasi-experimental designs do not use random assignment of groups and instead employ matching or other means of obtaining equivalence of groups.Quasi-experimental designs include time-series and counterbalanced designs.

__________ is the loss of subjects over the course of time.

Which of the following refers to accuracy or correctness in research.

Equivalence serves as a prototype for all other research designs and contains three elements: equivalence,pretests and posttests,and experimental and control groups.

Research designs that lack one or two of the three major elements of experimental designs- equivalence or experimental and control groups-are designated as pre-experimental designs.

Which of the following occurs when the researcher chooses nonequivalent groups for comparison?

Experimental designs sometimes called true experimental designs)are characterized by random assignment to treatment and control groups and include the classical,posttest-only control group,and Solomon four-group designs.

The three essential steps in resolving the causality problem are demonstrate that a relationship exists between the key variables,specify the time order of the relationship,and __________.

Time-series designs measurement of a single variable at successive points in time.

Which of the following refers to the tendency of groups that have been selected for study on the basis of extreme high or low scores to regress or move toward the mean or average on second testing?

__________ refers to accuracy or correctness in research.Internal factors question the internal validity of research,whereas external factors impugn the external validity of findings.

The one-group before-after design,or one-group pretest-posttest design,eliminates possible pretest reactivity by studying both an experimental and a control group after the experimental group has been exposed to some treatment.