Question: We often hear that in practice, not enough data of sufficient quality, consistency, recency, etc. is available for feeding into mathematical optimization models. Example: my university wanted to plan/optimize their weekly timetable using an integer program, but they did not know the number of rooms (let alone capacities, availabilities, equipment, location, etc.), they did not know the preferences of professors, nor which courses they actually taught (the system listed them as "responsible" for a course which did not imply that they were actually teaching that course!); they didn't know the number of students to expect in a course. I could contribute a lot of such stories.

Now, many companies (truthfully) claim that they collect data. E.g., sensor data from production, temperatures, filling rates, number of faulty products per hour, web clicks, customer orders, energy prices, etc., etc. I can't really grasp what makes we reject such data as "suitable" for optimization, and I am looking for a definition of what "different kind of data" needs to be collected in order to feed a typical mathematical program for e.g., timetabling, production planning, facility layout, or designing tariff zones. I thought for a while that the notion I am looking for is "actionable", but this doesn't capture it. Ideally, I would like to contrast this "optimization data" to data that is typically fed into machine learning algorithms (which extrapolate, cluster, predict, find trends, anomalies, patterns, etc.).

How would you call the number of students in a course, the availabilities of teachers, the capacities of rooms, the data that a course belongs to a certain curriculum?

Answer: 
I would just call it "planning data". I think it might be easier to convince an administrator that "planning data" needs to be recorded/captured than to sell them on "<insert techno-jargon phrase here> data". Administrators grasp what planning is (whether or not they are adept at doing it), and at some visceral level they probably realize that *not* planning is bad (which might make them a bit more inclined to make an effort to collect the data). If "planning data" does not do much to distinguish this sort of data from other sorts (salary data, student/faculty ratio, ...), perhaps that's a good thing. They already understand the relevance of the other data, and that it needs to be collected, so by association they might realize this data is also important.
I think, answers provided so far are great. When talking to professionals in the field, I second Nikos and call them "parameters" and cross my fingers they know the difference between a parameter and a variable (which is a bleeding wound between the OR profession in Industrial Engineering and OR profession in Business Administration). On the other hand, practitioners usually have a hugely different understanding of what "data" mean. They call every number or descriptive text gathered "data," which is hard to argue as they are right by the definition of *data* being like: "Come, come, whoever you are [Mevlana Jelaluddin Rumi]."

To kindly express the notion in my mind "I cannot do this so-called optimization stuff without you giving me the right data, dude!" I would just tell the practitioner: "I need the *problem data*" and define what I mean by it. Have I been successful so far? I don't know, I am only 30... I need to collect more data to answer whether this was a successful approach :)