Study suggests grading leniency is result rather than cause of low grading reliability

Professors love to hate grade inflation, saying course marks aren’t as meaningful as they used to be. A new paper makes the case that easy grading is actually a symptom of poor assessment practices rather than a cause and that, either way, reducing leniency in grading may lead to more accurate assessment. “The strong association between grading leniency and reduced grading reliability … calls for interpretations that go beyond the effect of restricting grades to fewer categories,” reads the paper, now available online in Studies in Higher Education. “One possible explanation is that grading leniency is the result, rather than the cause, of low grading reliability. Consider faculty members who suspect that their assessment methods are unreliable. This could occur in course subjects in which assessment of student performance requires subjective and complex judgment.” Less “flattering reasons” for low grading reliability include “badly designed or poorly executed assessments,” the study continues. “Increasing grading leniency as a compensating mechanism for low grading reliability can be rationalized as an ethical behavior because it avoids assigning bad grades to good students. It is also a prudent strategy because, though students may accept high and unreliable grades, they might begrudge low and unreliable ones.” “The Relationship Between Grading Leniency and Grading Reliability” is based on a data set pertaining to 53,460 courses taught at one unnamed North American university over several years. All sections included 15 or more students with passing grades, and failing grades were tossed out of the analysis to avoid any biasing effect on average grades. The primary focus was whether grades were reliable measures and whether they were lenient. Results suggest they're often neither, though there was plenty of consistent grading. A leniency score was computed for each section as the “grade lift metric,” or the difference between the average grade a class earned and the average grade point average of the class’s students at the end of the semester. So if a course section’s average grade was B, but the students’ average GPA was 3.5, then the “lift” score was -0.5, indicating tough grading. A positive score indicated lenient grading. “The core idea is that high grading reliability within a department should result in course grades that correlate highly with each student’s GPA,” reads the study, written by Ido Millet, a professor of business at Pennsylvania State University at Erie. Course section grading reliability scores were computed based on the same logic. So, in an extreme example, a section in which high-GPA students received low grades and low-GPA students received high grades earned a low reliability score. Grading reliability averaged 0.62, meaning that in...

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