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Jeremy Jewell on Using Wait List Control Groups in Evaluation

Hi, my name is Dr. Jeremy Jewell, and I am an Associate Professor in the Clinical Child and School Psychology Program at Southern Illinois University Edwardsville. For several years, I have helped our local probation department evaluate various risk assessment measures as well as programs for probationees.

When evaluating the effectiveness of a program, one of the best models to do so is to implement either a typical experimental / control groups model, or even to use a placebo control group if possible. However, in doing so, one may often run into the ethical dilemma of withholding a potentially helpful treatment for half of the participants. While this is probably more acceptable to researchers, it is often unacceptable to stakeholders. Sometimes, pushing stakeholders to go with an evaluation design that has the most research value may overlook stakeholders’ consideration of the ‘human element’, which in this case is the problem with allowing only some of the participants to receive a potentially helpful program. This can be a political pitfall that should be avoided if possible.

Hot Tip: A design that may be a good compromise is the use of a wait list control group. With this design, all participants eventually receive the program or intervention, but the design still allows for the control of many variables (with the exception of the placebo effect). So, let’s say you are evaluating the effectiveness of a six-week program using a pre/post test. You would randomly assign your participants to either the experimental or wait list control group. Then, administer the pretest to all participants just prior to when the experimental group begins the program in week 1 (of course the wait list control group would not begin the program yet). Then, the experimental group would receive the program in weeks 1 thru 6 and you will administer the post test to both groups at the end of week 6. In weeks 7 thru 12, you will deliver the program to the wait list control group.

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2 thoughts on “Jeremy Jewell on Using Wait List Control Groups in Evaluation”

  1. Michail Chantzis


    Thank for the information provided, it has been really helpfull to reach a better understanding of the waiting list group and how it should work in a study.
    I wonder though if you could provide me with some insight as am i dealing with a bit of a problem regarding the work im into at the moment. Working on my thesis i have designed an intervention with an intervention waiting list control group. So my major querry is over statistics what should i do with the data. Contrast the intervention group to the control. Then maybe contrast the control that became intervention data to the first intervention group?

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