Reisel, J., Shneiderman, B. (Oct. 1986)
An experiment was conducted in which four window sizes (10, 22, 60 and 120 lines) were compared for their effectiveness for program reading. The largest window, in which the entire program could be seen at one time, was found significantly better, in both time to complete the reading task and the number of correct answers in the reading task. Subjects also preferred the larger windows to the smaller windows.