In relation to my question on Mathematics.SE, I would like to know what English words would fit the best to describe the expected amount of information that will be gained by learning the answer to a given question or by learning the responses to a given questionnaire.
The word should describe the question or the questionnaire, not the answers. Thus, words like "informativeness" or "information value" would fit poorly, because the common view is that the information is contained in answers, not in questions (though in fact both are important).
For example, the value that is to be described is a priori higher for the question "What is your favourite dish?" than for the question "Do you like French fries?" It is also a priori higher for the question "Are you married?" than for the questions "Do you pay taxes?" and "Are you a lawyer?" (assuming nothing is known about the person being asked, the answers to the last two questions are easier to guess in advance -- "yes" and "no" respectively).
The question "What is your favourite dish?" has higher foo (or more foo) than the question "Do you like French fries?"
The total foo of a questionnaire composed of completely independent questions is the sum of the foos of its questions.
I know that this is an instance of entropy value, but I am looking for a more common and intuitive term, if such exists.