Adjuncts are better teachers than tenured professors in introductory courses

Over the past decade (or more) there has been a rise in the number of contingent (or casual) teaching positions at universities, in New Zealand and around the world. They come in various forms, and have various titles like teaching fellows, adjunct professors, and so on. What they share in common is that, most of the time, they are positions that only involve teaching, and usually only undergraduate classes. That is, there is no explicit research component to the position (although some of those working in these positions may be completing doctoral studies, etc.). They are also fixed-term casual positions, with contracts that may or may not be renewed.

Given that these positions are fixed-term with no commitment from the institutions to renew them, this distinguishes these positions from continuing positions, or tenured (or tenure-track) positions. In particular, if a fixed-term teacher does a poor job of teaching, then they may not be offered future teaching contracts. In contrast, tenured (or continuing) faculty members don't face the same pressure for teaching quality. So, one would expect that contingent teaching faculty would, on average, be better teachers than faculty who have continuing contracts (or those who are tenured).

A forthcoming paper in the Review of Economics and Statistics (ungated earlier version here) by David Figlio and Morton Schapiro (both Northwestern University) and Kevin Soter (Greatest Good) tests whether this is the case. Specifically, they attempt to answer the question: "Do undergraduates taught by contingent faculty learn as much as those taught be tenure tract/tenured faculty?".

The authors use data from eight years (2001-2008) of freshmen students at Northwestern (over 15,000 observations in total), looking at the probability that these students take another class in the same subject, and looking at the grades in that subsequent class. There are a number of interesting findings, starting with:

...a contingent faculty member increases the likelihood that a student will take another class in the subject by 7.3 percentage points (9.3 percentage points when limited to classes outside the student's intended major) and increases the grade earned in that subsequent class by slightly more than one-tenth of a grade point (with a somewhat greater impact outside the intended major).

In their preferred specification, the effect on grades is about half as large as reported in that quote, but is still statistically significant. They also look at what is driving the results:

...the most outstanding contingent faculty members and most outstanding tenure track/tenured faculty members perform essentially identically... But the bottom quarter of the tenure track/tenured faculty have lower value added than the bottom quarter of the contingent faculty...

In other words, the best teachers (tenured or contingent) are similar in their effect on student learning, but the worst tenured professors are much worse than the worst contingent teachers. Which supports the expectation I laid out at the beginning of the post. The authors also find that the differences between contingent and tenured faculty are largest and most significant among faculty that have the most experience, and that the differences are largest and most significant for the subjects with the toughest grading standards, and for the subjects that attract the highest quality (measured by SAT scores) students.

Finally, they investigated whether (among the tenured faculty) the most outstanding researchers are better or worse teachers, and:

...find no difference in teaching outcomes compared to tenured faculty who have not received the recognition [for research excellence]...

Based on my experience I find that last bit a little surprising (or not - they are comparing good researchers with truly excellent researchers), but the rest makes a lot of sense. Teaching and research both require investment in terms of time and effort. While some may argue that teaching and research are complementary, I'm not convinced. I think they're substitutes for most (but not all) faculty (I'll cover more on that in a post in the next week). Faculty who do teaching but little or no research can be expected to put more effort into teaching than faculty who do a lot of (particularly high quality, time intensive) research. So, contingent teaching faculty should do a better job of teaching on average. These results seem to support that.

Does this mean that we should replace a bunch of the most experienced tenured professors with fixed-term teaching fellows? Not necessarily. The research only looked at teaching at introductory level, and doesn't tell us much about the quality of teaching at higher (especially graduate) levels, where you might expect research-oriented faculty to have an advantage. It does tell us that choosing the best teachers for introductory courses is important in attracting the right students into future courses though.

[HT: Marginal Revolution]