Two days ago, I wrote about a hypothetical question of "bad research."
I argued that "bad research" was not necessarily an appropriate description of the specific situation described (writing a dissertation as if it had been aimed to find what was actually a post hoc discovery). I argued the point primarily from the perspective that research is essentially post hoc--that it must be if it is to have a truly open and exploratory character, and that research has no claim to purity, either from a historical analysis or a logical one (following Paul Feyerabend).
But on a related note, we also want to ask about the general question of expediency and ethics. What if it were "bad research" to present a post hoc analysis?
Each person must answer the ethical question individually, and for each of us, relativist, or absolutist, we make our decision to act according to some calculation when the situation is ambiguous. To take an extreme example, a person following an absolute moral code (e.g., "Thou shalt not kill") may still find a situation where something else is of higher moral valuation such that violating that code is morally acceptable.
Different acts have different values. In academia, plagiarism is a primary crime, as is inventing data or altering data to get desired results. Compared to such violations of academic ethics, even a position that holds that post hoc analysis is "bad", would not consider it a violation of research ethics on the same order of magnitude.
Balanced against these ethical issues, we need to ask also about expediency: we want to finish the project. Following the recommendations of our committee is almost always expedient (but most definitely not always), and it would be wise to follow suggestions whenever possible. One does not wish to compromise one's ethics for expediency, of course.
There's no clear answer. We each make our own answer. As a coach, I tend to lean towards expediency when matters are small. I would never recommend plagiarism or data faking as an expedient route: the potential backlash is too great; the potential for a real disaster (being kicked out of an academic program and destroying one's potential academic or professional career). But "bad research"? How highly must one balance "bad research" against expediency as an ethical issue?