The average length of United States medical school psychiatry clerkships has been gradually declining over the past 30 years, from 6.4 weeks, in 1982 (1), to 6 weeks, in 1999 (2), to 5.5 weeks, in 2010 (3). Alexander and Bostwick report being recently put in the unenviable position of having the shortest required psychiatry clerkship in North America (4). We can all empathize with the frustration that this reduction might entail, given that their 3-week clerkship is half the length recommended by the Association of Directors of Medical Student Education in Psychiatry in its 2006position statement (5).Alexander andBostwick are to be commended for moving beyond their frustration to examine the impact of the reduction in clerkship length on their students’ shelf scores in a thoughtful and scholarly fashion. Their challenging situation offers us an opportunity to think about the meaning and impact of clerkship length. On the most concrete level, clerkship length might be viewed as an indicator of worth by a number of different stakeholders, from deans to department chairs to teaching faculty to students. Medical school faculty committee meetings devoted to divvying up time within an impacted curriculum can generate intense “turf battles” and hard feelings. Although these disputes are often fueled by financial considerations, the significance of the implied value judgment that accompanies those distributions should not be minimized. Clerkship directors and faculty faced with a reduction in clerkship length might feel as if they have been demoted, and that a value judgment has been made against them and their field. Psychiatrists are particularly vulnerable to this assumption, given the uphill battle that we and our patients have faced for full acceptance within the house of medicine. Recognizing that time-allocation and prominence of placement in the curriculum are important aspects of the “hidden curriculum,” (6) psychiatric educators must be concerned about the underlying message that a shortened clerkship sends to students and colleagues.The importance of these factors may be reduced but will likely not be eliminated by such alternate models for clinical training as the longitudinal clerkship experience (7). The longitudinal clerkship experience is an example of an alternate model for clinical training. What is the impact of psychiatry clerkship lengthreduction on students’ acquisition of knowledge?Alexander and Bostwick reasonably turn to shelf examination scores to address this question. As their manuscript’s title indicates, “shorter psychiatry clerkship length is associated with lower NBME psychiatry shelf exam performance.” As they acknowledge, their ingeniously-obtaineddata donot allow them to move beyond that association to make any conclusions about causality. First, their comparisons are limited by the lack of randomized assignment; the difference in shelf exam performance between the groups could be explained by the greater interest in psychiatry held by the students who chose the additional 3-week exposure. Second, a significant difference in shelf exam scores was found only in comparing those students who spent 6 weeks on their psychiatry clerkship with students who spent 3 or 4 weeks. Third, students’ performance on the shelf exam was not significantly different between those students who spent 4 weeks from those who spent 3 weeks in their psychiatry clerkship. It is possible that the data reflect a genuine reduction in acquired knowledge when the clerkship length is reduced to 4 weeks from 6. Furthermore, it is possible that the lack of difference between the exam scores of students who spent 4 weeks on the clerkship from those who spent 3 weeks reflects a genuine lack of difference in knowledge acquisition. It may be that there is a floor effect, and that students will “crack the books” sufficiently to learn the knowledge Received February 3, 2012; revised February 29,March 14, 2012; accepted March 20, 2012. From the New York State Psychiatric Institute and the Department of Psychiatry, the College of Physicians and Surgeons of, Columbia University, New York, NY. Send correspondence to Dr. Cutler; e-mail: cutlerj@nyspi.columbia.edu Copyright © 2012 Academic Psychiatry