Powers, D. E., & Fowles, M. E. (1996). Effects of applying different time limits to a proposed GRE writing test . Journal of Educational Measurement , 33 (4), 433–452. https://doi.org/10.1111/j.1745-3984.1996.tb00500.x

Participants wrote two essays, one with a 40-minute time limit and one with a 60-minute time limit. Half of the examinees wrote the 40-minute essay and half wrote the 60-minute essay first.

Study participants were 304 paid volunteers recruited from the pool of examinees who took the GRE General Test between January and May of 1994. Ethnic minority and nonnative examinees were over-sampled, and in order to ensure sufficient heterogeneity with respect to writing ability, letters of invitation made a special plea to those students who did not consider themselves strong writers.

Each participant wrote two full-length essays. The examinee had been sent one topic before the test and encountered the other topic for the first time at the test administration. The essays were scored holistically on a 6 point scale by two trained readers. Questionnaire data were collected regarding perceptions of adequacy of time limits, an estimate of how quickly Participants were able to write, and a judgment of how well the Participants had performed on the writing tasks administered. Participants also submitted a course-related sample of writing that they had completed as an undergraduate assignment. Several weeks after the administration, participants completed a 12-item inventory of writing accomplishments on which they indicated which of several writing accomplishments they had made.

Essays written under the 60-minute time limit received moderately higher scores, on average, than did essays written under the 40-minute time limit.