GoKawiilUniversity students pursuing graduate degrees are seeing their grades rise.Credit: ETham/Alamy
The grades attained by master’s and PhD students have risen over the past two decades, according to a study conducted at a large public university in the US Midwest.
But, without a demonstrable improvement in the quality of students’ work over that period, the increase likely amounts to what researchers call ‘grade inflation’. This phenomenon has been well documented at secondary schools and undergraduate institutions around the world1,2, but this study represents one of the first reports of it at the graduate level. Not all graduate programmes across the globe assign grades to students, but many in the United States do.
The analysis, published today in PLoS ONE3, used data from nearly 25,000 master’s students and 16,000 PhD students admitted to more than 150 graduate programmes at the university from 1999 to 2020.
Over these two decades, students’ cumulative grade point average (GPA) — the average grade earned during their programme, measured on a scale of 0 to 4 — increased. The mean GPA for master’s students climbed from 3.70 for those admitted in 1999 to 3.82 for those admitted in 2020. Among PhD candidates, it rose from 3.74 to 3.82 over the same period.
Source: Ref. 3
To ensure that the inflation was not caused by a genuine increase in students’ abilities, the researchers conducting the analysis adjusted their data using the incoming students’ scores on a standard US admissions test, the Graduate Record Examination (GRE). The authors also adjusted for changes to the university’s demographics over time to account for accompanying fluctuations in grades because of students’ varying access to educational and other resources. Grades still went up after this accounting (see ’Going Up’).
The reasons behind grade inflation are unclear. But one hypothesis is that university professors might be incentivized to give higher grades to receive better student evaluations or to boost enrolment, says co-author Vivien Lee, who studies industrial-organizational psychology at the University of Minnesota in Minneapolis.
Reaching the top
“What’s really striking is that we are seeing grade increases, even though 20 years ago grades were already high,” Lee says. Between 1999 and 2020, the gap between the average GPA for master’s students and a perfect 4.0 shrank by 40%, and for PhD students, it decreased by 31%, she adds. “As grades get closer to the top of the scale, they become less useful for differentiating students, and that’s what grades are typically used for,” Lee notes.