IP: "Median Years to Degree" in the recent Conference Board study

[David Farber <farber () central cis upenn edu>]

Date: Tue, 26 Sep 95 14:47:18 EDT
To: farber () central cis upenn edu (David Farber)
From: rick () cra org (Rick Weingarten)
Subject: Dave, FYI. Use as you wish.




A number of you have commented that the "Median Years to Degree" reported
for your program in the recent Conference Board study ranking CS
departments is significantly higher than your own data indicates.


Ed Lazowska of the University of Washington, with help from a number of
others, has diagnosed this.  A full description of the issue is available at:


        http://www.cs.washington.edu/homes/lazowska/myd.html


The data, itself, for CS is available in searchable form through CRA at
        http://cra.org/cgi-bin/RankCS.


In a nutshell, the measure labeled "Median Years to Degree," which is
widely interpreted to be "the median number of years that students spend
in this graduate program," is in fact best described as "the median number
of years from when the student first enrolls in any graduate program
anywhere, until the student receives his/her Ph.D."


Suppose, for example, that a student enters a Masters program immediately
after receiving his/her Bachelors degree, and graduates from this Masters
program in 2 years.  Then the student enters the workforce for 5 years.
At this point, the student enrolls in a Ph.D. program, from which s/he
graduates 4 years later.  The Ph.D.-granting institution probably feels
pretty good -- cranked this student out in 4 years!  But in the Conference
Board study, this student will weigh in at 2 + 5 + 4 = 11 years!


Other factors also are at play; full details are included in the web
page referenced above.