I have often remarked that I do not consider myself a scholar. It goes without saying that I also do not consider myself a research scientist. But my lack of research credentials was brought home to me rather abruptly by Dania Francis, the young advanced doctoral student whom I recruited, at the suggestion of the head of the Spencer Foundation, to assist me with the formulation of what is apparently called a “research protocol” for my new project at Bennett.
I had decided to select sixty of the incoming one hundred eighty-three Bennett Freshwomen for the Pilot Program I shall be running in AY 2012-2013. For various reasons, I wanted a representative sample of students, as determined both by their high school GPS’s [that is “grade point average” for my foreign readers] and by their status as either in-state North Carolina students or out-of-state students.
The Excel spreadsheet of the incoming students provided to me by the “Office of Enrolment Management” is organized in descending order by GPA, so, since I was selecting a third of the class for my Pilot Program, I thought the cool way to choose them would be simply to go down the list, tagging every fourth name. This produced a representative selection of GPA’s and, as I anticipated, close to a representative sample by geographic origin. Pretty good, yes? I then divided the sixty students thus selected into ten groups by simply opening a new field in the spreadsheet called “Group,” and then going down the list of sixty students [still arranged, of course, by GPA] and marking the fields numerically, 1 through 10, in order, thus producing ten groups, each of which had a range of GPA’s. I checked, and they also had a scattering of in-state and out-of-state students. Along about now, I was feeling pretty good about myself, thinking that I could do this without the help of a graduate student!
With mock modesty, I explained all of this to Dania, expecting her to exclaim, “But that is exactly the way it should have been done!” Fat chance. She looked at what I had done and said quietly, “I think you should choose the students randomly.” “But,” I replied, “My way has produced a selection that almost perfectly mirrors the entire class.” “Yes,” she replied, “but there may be hidden variables. I think the Spencer Foundation would prefer a random selection.”
Well, all of this was in aid of getting money from the Spencer, and my ego is not so large as to stand in the way of a grant, so I said, “How would you do that?” “Very simple,” she said [rather like explaining rain to a child], “we just assign them numbers 1 through 183, and then generate a random number sequence that selects sixty of them. Then we do the same thing to group them in ten groups of six each” [I hope I have that right.] She drove back to
Boston from , and had it all done by the next day. Amherst
I reported all of this to Mike McPherson, President of the Spencer. Here is his reply: “Sounds great. It's a good sign that she immediately recognized the need to use random assignment, since that option is available.”
Pretty clearly, I have a lot to learn.