Dr Norris,
I don't believe one needs to measure the results of the approach used by admissions staff to effect a change in overall retention. Indeed, one needs to scrutinize the performance metrics by which admissions staff are judged. I come from state schools and have a limited perspective on the for-profit arena. However, for the two schools I have worked for in the past year, admissions staff are soley judged on the following metrics: leads assigned, appointments, interviews, enrollments and starts. Once a student is started, the admissions rep need only monitor the student for a very finite period of time, roughly a week.
In fact, I have seen reps openly chastised for assisting enrolled students. The focus is supposed to be on generating new business, not tending to business that is already in the house.
If one wants admissions to be part of the greater retention process, the organization needs to make retention part of the performance metrics. It is a numbers game and the organizationally-induced myopia of the admissions cycle results in a mentality of instant gratification, not long-term objectives.
Just my thoughts.