Exam 10: Quasi-Experimental Designs and Program Evaluation

Experiments in natural settings are likely to differ from laboratory experiments on four critical dimensions: control,external validity,goals,and consequences.Briefly describe the nature of the difference for each of these four dimensions.

If the residents,staff,and facilities of a nursing home where a quasi-experiment was done are likely to be different from those in other nursing homes,then the findings of the study are likely to lack

Program evaluation is a hybrid discipline whose professional activity

The one-group pretest-posttest design is

Which of the following is likely to be the most important benefit from the use of program evaluation based on sound experimental methodology?

When two groups in a nonequivalent control group design do not differ on the pretest,the researcher can conclude that

Which of the following threats to internal validity is controlled in the nonequivalent control group design?

When,from the outset of a study,differences exist between the kinds of individuals in one group of an experiment and those in another,there is a potential threat to internal validity called

A psychologist examines the effect of a new therapy by first assessing patients' symptoms using a pretest,then administering eight weeks of therapy,and then administering a posttest.Based on this research design,the psychologists will be able to

In clinical trials involving tests of new medical treatments it may be extremely difficult to get patients to agree to be randomly assigned to either the treatment or the control group.In these situations researchers can use

Students on two college campuses serve as treatment and control groups in a study investigating the effectiveness of an alcohol-abuse prevention campaign.A well-known student on one of the campuses dies of alcohol intoxication in the course of the study;students on the other campus did not learn of the student's death.The reaction of other students to the student's death on their campus could represent a potential threat to the internal validity of the study called

A researcher was interested in determining whether more frequent breaks (i.e., "coffee breaks") in a business setting would help employees to be more productive. With the cooperation of the management, employees on one floor of the corporate offices were allowed to take a 10-minute break each hour (at any time) between 8:00 and 11:00 A.M. (for a total of 30 minutes). The comparison group comprised employees on different floors who followed the usual corporate policy of taking a 30-minute break sometime during the morning (at any time). Measures of productivity were gathered for each employee according to his or her job (e.g., number of reports written, number of sales made, etc.). A time series analysis was applied to compare the productivity of both groups of employees for six months before and after the intervention (started in July). Quite surprisingly, the productivity of both groups increased following the onset of the intervention, suggesting to the researcher that the timing of breaks makes no difference. -Explain why the "Hawthorne effect" may have influenced the results of this study.

A student used a nonequivalent control group design to examine the effectiveness of a computer module the library uses to introduce first year students to the library's resources.Which threat to internal validity could she potentially rule out by examining the pretest scores for both groups?

When people's performance changes because they are enthusiastic or energized by an intervention,the results of a study are likely affected by

An argument for the internal validity of quasi-experiments

The effect of a treatment in a simple interrupted time-series design is indicated by

One of the main ways that true experiments differ from quasi-experiments is that true experiments use

Among the following designs,which allows researchers to rule out the most threats to internal validity?

A simple interrupted time series design provides a reliable measure of the effect of the treatment because there are many observations both before and after the treatment.The major threat to internal validity in this design is

One factor that may make it difficult to interpret the result of even a true experiment in a natural setting is contamination (when there is communication of information about the experiment between groups of participants).Briefly describe the three types of problems that can result from contamination.