Exam 10: Quasi-Experimental Designs and Program Evaluation

A clinical psychologist examined the effect of a treatment designed to reduce the amount of cigarette smoking in the day room of an inpatient psychiatric facility.His treatment consisted of a several components to maximize its potential effectiveness (e.g.,increasing the number of available activities; giving patients responsibility for care of the unit's plants,fish,etc.; the opportunity to exchange cigarettes for positive reinforcers).At the end of three months,his data indicated that cigarette smoking had declined significantly.Based on this,he is able to conclude that

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

At a large university,a group of education specialists tested the effectiveness of a new academic improvement course.Students seeking help at the university counseling center because of academic difficulties were asked to participate in this 4-week program.Only students who were judged to be deficient in reading comprehension and other study-related skills were chosen for the program.Students who sought help at the counseling center for emotional difficulties were included in the study as a comparison group.These students received the usual treatment offered at the counseling center.A group of 30 students completed the academic-improvement program at the counseling center.Average test grades from the students' courses for the two groups were compared before (midterm exams)and after (final exams)the program.Analyses revealed that a statistically significant majority of the students were doing better in school after completing the academic-improvement program than before. Identify and describe two threats to internal validity in this study.That is,show why there are at least two plausible alternative hypotheses for the obtained change in grades other than due to the academic-improvement program.

Even when pretest scores are the same,on average,for treatment and comparison groups in a nonequivalent control group design,the two groups may not be equivalent because

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

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

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.

Strong evidence of a treatment effect in a time series with nonequivalent control group design is indicated by

A psychologist tests the effect of an incentive program (i.e.,positive reinforcement for desired behavior)in a residential treatment facility for delinquent youth.He randomly assigns one building of the large facility to receive the treatment.Residents in a second building serve as a control group.During the course of the one-month study,an event happens in the treatment group that forces full lockdown of the building for one week.The threat to internal validity the psychologist must consider is

A human services agency was interested in finding out whether establishing a food distribution center in their community would provide a service the community would use.Which of the following types of assessments in program evaluation would this agency find useful for this question?

A researcher trains observers to complete checklists while observing children's behavior on the schoolyard during recess.Over the course of the study,observers become more reliable in their observations.Any effect of a treatment in this study might be confounded with an ____________ threat to internal validity.

A physician wants to test the effectiveness of a new allergy medication.The physician consults a researcher who regularly conducts clinical trials.The physician tells the researcher that she has a backlog of 100 patients she is treating effectively with the current leading medication,but who could potentially benefit even more from the new medication.The researcher recommends that the physician do a true experiment because of the availability of

When events that occur during the course of a study have a different effect on one group of participants than on another,the possible threat to internal validity is

Perhaps the greatest difference between basic research and program evaluation lies in the differences in

Distinguish between evaluation of outcome and evaluation of efficiency as these are used in program evaluation.

The most critical defining characteristic of a true experiment is often seen to be a high degree of control over the

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

Why is the nonequivalent control group design superior to the one-group pretest-posttest design in terms of controlling for threats to internal validity?

A study using a simple interrupted time-series design examined people's responses to the September 11,2001 terrorist attacks using a questionnaire measure of religion and faith.Archival data were available for the population four months before and after the attacks.The researchers observed that people's religious feelings and faith increased in the months following the attacks.One threat to internal validity that should be considered in this study is

In the context of conducting experiments in natural settings,random assignment of participants to conditions is