The underspecification was intentional, so that people may answer according to what their preferred decision theory.
Ahh, survey question. In that case may I suggest leaving the ‘rational’ there but removing the ‘utility maxisers’. I think that would get you the most reliable information of the kind you are trying to elicit from the response. This is just because there are some whose “preferred decision theory” and specific use of terminology is such that they would say the ‘rational’ thing for Bob to do is to cooperate but that a “utility maximising” thing would be to defect. I expect you are more interested in the decision output than the ontology.
Ahh, survey question. In that case may I suggest leaving the ‘rational’ there but removing the ‘utility maxisers’. I think that would get you the most reliable information of the kind you are trying to elicit from the response. This is just because there are some whose “preferred decision theory” and specific use of terminology is such that they would say the ‘rational’ thing for Bob to do is to cooperate but that a “utility maximising” thing would be to defect. I expect you are more interested in the decision output than the ontology.