Craft Reports PRACTICAL TECHNIQUES FOR IMPLEMENTING TRUE EXPERIMENTAL DESIGNS

This note suggests that it is sometimes possible to apply true experimental designs in field settings by takmg advantage of the constraints under which programs or experimental treatments must operate. In a research study requiring classical treatment and control groups, practical methods for implementing true experimental procedures in public schools had to be devised and applied. These solutions to a problem often encountered by evaluators are presented here. C7) recurrent problem in evaluation research is that of obtainingrecurrent control or comparison groups. Although assigning subjects randomly to either a treatment or control group has long been regarded as fundamental to experimental research, a variety of practical con-straints confronted in field situations often seems to prevent the applica-tion of such random assignment. As a result, instead of implementing true experimental designs, researchers may settle for any of a number of quasi-experimental alternatives which may lay open serious threats to a study’s validity (Campbell and Stanley, 1966). Here it is suggested that the constraints commonly accepted as obstacles to implementin