Hey savvysearch,
Thank?s for asking this question, I was just going to post a similar question.
I can only guess about the reasons research is preferred by the admission staff. Is it an indicator of one?s ability to think critically and logically to solve problems? I know it can make ones personal statement a little more interesting.
A similar question would be, how could research benefits an applicant for admissions, and how can one capitalize on the experience?