The Gap is Everywhere!

Of late, I have been writing about problems that differential grading causes, both in terms of employers and graduate schools picking the “wrong” students, and in terms of dissuading students from studying certain subjects.

I must admit that my arguments and analysis of different grading schemes in different disciplines was based on one crucial assumption:

The intellectual quality of science students is no worse than that of

students in the humanities, arts, or social sciences.

I readily admit that, if science students tend to be less intelligent than humanities students, then they deserve poorer outcomes. However, there seems to be little evidence to this effect so I shall not belabor this point.

More importantly, I have recently run across several studies, which support the idea of grade normalization across subjects

In a landmark study done by Durham University in the UK, which tracked over a million students taking A-levels and GSCE exams, researchers found that students of equal ability received approximately a full letter grade lower in the sciences than in subjects like drama and English. The study was commissioned by the Royal Society (the world’s oldest professional body for the sciences, whose membership includes the likes of Newton and Hawking) in order to provide evidence that differential grading schemes may be contributing to a decrease in the number of students pursuing science degrees in the UK.

While my analysis in my last post was solely regarding grades at Dartmouth, it appears that the same differential grading practices take place all across the US as well. An online magazine article describes studies done at Cornell, comments by a Stanford Business School professor, and several other pieces of evidence which all point to the idea that lower grades in sciences can dissuade students from pursuing science degrees.

It is also evident that these grading differences between the sciences and humanities have been there for many decades. The question thus arises, why did they arise and why has no one corrected them, despite the easily available evidence as to their existence?

How Wide is the Grading Gap?

Introduction

While most people concede there is a grading gap between the sciences and the humanities, few are aware of big it is. In order to determine precisely how wide the gap in grading is between various areas of study, I analyzed the grades at my alma mater. Dartmouth is one of the few colleges that publically makes grading information available on the web. And there are fewer still colleges that publish course level data, such as Dartmouth and Cornell do.

In particular, in an attempt to combat grade inflation, Dartmouth started placing median grades next to the student’s grade on his or her transcript for each course with an enrollment of 10 students or above. Additionally, Dartmouth College publishes a list of all courses that fit this enrollment criterion along with their median grades on its registrar’s website.

Methodology

In order to analyze the grading gap between different broad disciplines, I obtained the median grades of all available courses on the website, totaling to 3166 courses taken across the last two years. I then placed each course into one of four categories:
1. Arts
2. Humanities
3. Soft or Social Sciences
4. Hard Sciences.

After classification of each course, I calculated the mean of all the median grades in each discipline. You can view the results here.

In looking at the data, there are some useful things to know. At Dartmouth, an “A” is a 4.0, A- is 3.66, B+ is 3.33 and so on. Furthermore, the median student at the time of graduation has approximately a 3.3 GPA. The cut-off cumulative GPAs to be in the top 5%, 10% and 15% of students at the time of graduation are 3.89, 3.77, and 3.59, respectively.

Results

In light of these reference points, the results are quite shocking. A science student who achieved the median grade in each of his or her courses would have a GPA in the middle of his or her graduating class, whereas a humanities student achieving the same feat in his or her courses will receive honors for being in the top 10% or 15% of all graduating students.

There is a 0.43 GPA gap between arts and hard sciences students and a 0.23 GPA gap between humanities and hard sciences students, which is needless to say, significant. A difference in 0.23 grade points, ceteris paribus, makes the difference between getting into a top professional school or not, between getting a prized job or not, between being awarded honors at graduation, or not.