The increasing use of adjunct faculty in American colleges, who make up 76 percent of American college instructors and are often paid poorly and ineligible for health care or other benefits, is cause for concern among academics. Their actual job security and financial health is a sort of obvious human rights problem, but many also argue they’re not really qualified to teach students. According to a 2007 New York Times article, “adjuncts… have less time to meet with students, and research suggests that students who take many courses with them are somewhat less likely to graduate.”

But it turns out they might still be pretty good teachers.

According to new research by Northwestern University president Morton Schapiro, professor David Figlio, and consultant Kevin Soter of The Greatest Good, freshmen taking classes from adjunct professors at Northwestern actually performed better than those taking classes taught by tenure-track faculty. As the researchers explain:

This study makes use of detailed student-level data from eight cohorts of first-year students at Northwestern University to investigate the relative effects of tenure track/tenured versus non-tenure line faculty on student learning. We focus on classes taken during a student’s first term at Northwestern, and employ a unique identification strategy in which we control for both student-level fixed effects and next-class-taken fixed effects to measure the degree to which non-tenure line faculty contribute more or less to lasting student learning than do other faculty. We find consistent evidence that students learn relatively more from non-tenure line professors in their introductory courses. These differences are present across a wide variety of subject areas, and are particularly pronounced for Northwestern’s average students and less-qualified students.

Freshmen who took a class taught by adjunct professors were 7 percent more likely to take more courses in that field, and also likely to earn higher grades (between .06 and .12 grade point) in subsequent courses than if they took the same class from a tenure-track professor.

So what can we conclude from this? Well, it’s hard to know. As Jordan Weissmann puts it over at the Atlantic:

As the authors note, this paper only looks at freshmen. Tenured professors might very well might do better in advanced junior and senior-level courses where they can incorporate their own research and special expertise into their curriculum and have a chance to work with students who’ve accumulated a bit more specialized knowledge. Also: Northwestern is a tony private university that attracts highly qualified faculty to work as adjuncts and non-tenured instructors. Who knows if these results would hold up at a typical state university.

With more than three-quarters of college instructors now employed in this manner it’s a very good idea to start to evaluate such teachers in terms of what they’re specifically there to do: teach students.

One concern I have with generalizing too much from this study is that there are good adjunct faculty and bad adjunct faculty. Are all adjunct faculty as good as those evaluated in the study? Probably not. Indeed, Northwestern might be exceptional in its ability to secure the very best adjuncts to teach its classes to freshmen. The average adjunct is probably a very different sort of teacher.

Daniel Luzer

Daniel Luzer is the news editor at Governing Magazine and former web editor of the Washington Monthly. Find him on Twitter: @Daniel_Luzer