## Methodology for PhD rate calculation

The "PhD productivity rate" estimates the proportion of an institution's bachelor's degree recipients that go on to obtain the doctorate degree within 9 years.

The data sourceĀ for doctoral degree counts and the baccalaureate origins of these is the National Science Foundation Survey of Earned Doctorates, which regularly attains response rates in excess of 90%.

The PhD "rate" is calculated as the number of doctorate degrees earned by bachelor's degree recipients at the listed college during a ten-year period, divided by the total number of baccalaureate graduates (data source: National Center for Education Statistics) from that institution during an offset ten-year period nine years earlier.

The current example shows the sum of all doctorates attained from 2001 through 2010 by Bryn Mawr graduates, divided by the sum of Bryn Mawr graduates from 1992 through 2001.

Science and engineering (STEM) includes psychology and social sciences, as per NSF definitions.

Method for estimating female PhD rates for 2007-2010:
Bryn Mawr is a single-sex institution and so the most appropriate benchmark for comparison with other institutions is the female-only rate, particularly for many STEM fields in which women are known to be underrepresented.

Beginning in 2007, the National Science Foundation stopped releasing data by gender at the level of individual baccalaureate institutions, due to concerns about confidentiality.

For the years 2007-2010, this report estimates the number of PhDs awarded to females based on the ratio of female PhDs to total PhDs for the 6-year period 2001-2006, multiplied by the total number of PhDs awarded for the period 2007-2010.

For instance, suppose institution X awarded 20 PhD degrees in the years 2007 to 2010, and 100 PhDs during the years 2001-2006. The gender of the twenty 2007-2010 PhD recipients is unknown, but suppose we determine that 40% (i.e., 40) of the 100 PhDs awarded during the years 2001-2006 were female. It is reasonable to estimate that the proportion of females among those 20 PhDs awarded from 2007 to 2010 would also be 40% (i.e., eight).

This was the methodology used to estimate the number of female PhDs awarded for all baccalaureate institutions for the years 2007 to 2010. The estimates for these years were added to the actual figures for 2001 to 2006 to obtain the estimate of female PhDs awarded for the most recent 10-year period from 2001 to 2010.