What are the benefits and drawbacks of a professor being interdisciplinary when they seek tenure?

Question

Possible benefits: More grant money through other departments

Possible drawbacks: A significant fraction of their research might not be seen as research that benefits the department's standing in the area.

But what about others?

Answer 1

If you've been doing interdisciplinary research for five years, and now approach the tenure process without a clear idea of how to sell your case, consider it failed, and start looking for a job elsewhere, before you are under an immense pressure of finding a good job in a one-year grace period after the end of the world as you know it.

If you were hired specifically for interdisciplinary research, and your offer letter stated that, and your time was split "50% + 1 hour in computer science + 25% in department of Roman languages + 25% in agriculture", with a clear explanation as to how you are to be evaluated by each of the parties involved, then these explanations should have served as the guidelines to build your research program. If you were hired to do the theory of parallel computing, but later decided that it would be cool to do some extra work in Roman languages because you liked their research questions, and thought you could contribute with your data mining algorithms that would uncover nuances of how Latin and French are interconnected (and you did, by their standards); and you proposed some GIS tools for horticulturalists to use that have become the industry standard software -- that's all fun and fine, but if you did not discuss that with your CS chair, this was likely a waste of time, as in terms of parallel computing, this time was as good as playing squash. Your annual reviews in the main department should have indicated so, if your department would ever care to guide you (not all departments do, though).

Spending time in another discipline is very fruitful for finding interesting research problems (as typically most disciplines don't talk to one another, and there's a wealth of problems to be solved using other disciplines' tools), but it also means that you have had less time to spend in your home discipline, which nearly inevitably means a weaker CV: fewer grants, fewer publications, lower quality research. (That's essentially Suresh's last point).

Answer 2

I don't think either of the points mentioned above are relevant. If there's the potential for more grant money there should be evidence of it by tenure time. As for "benefit to the department" the real question is how good the work is, and if it's recognized in the larger communities.

From the tenure-seeker's perspective, one potential benefit is a much larger pool of letter writers. A downside is the "jack of all trades" problem, where each community can only comment on a portion of the work, and the work itself is not perceived as excellent in any individual community.

Answer 3

Interdisciplinarity can help or hurt, depending on how your work is perceived by the experts in each of the two (or more) fields. If you are seen by the experts in field A as doing excellent work in A, and if you're also seen by the experts in field B as doing excellent work in B, then this situation improves your chances for tenure. If, on the other hand, the experts in field A say something like "not so great in A, but it's impressive that (s)he also does B," while the experts in field B say something like "not so great in B, but it's impressive that (s)he also does A," then you're in trouble --- the people evaluating you for tenure will see "not so great" and ignore "impressive". So, if you can do excellent work in both areas, do so, but if you can't, then it's better to do excellent work in one field than mediocre work in two.