Can my professor require, at the penalty of point loss, that I actually contact my family members?
No, because for all the professor knows, you might be an orphan without any living family members.
However, I suspect the request is meant in less literal a way than what you are taking it for. You should clarify this with your professor.
The issue is that the professor probably wants to create such an assignment that involves a number of subjects, without overburdening any third parties, while at the same time avoiding that everyone asks their classmates and all answers to the assignment are based upon essentially the same sample.
Some examples of similar suggestions to students that I find completely normal:
- "Have your girlfriend/boyfriend proofread your thesis before submitting it."
- "Ask your parents to use your prototype before running the study."
None of these means that you really need to ask these specific people, or that you shouldn't ask anyone else. They are just a way to express that you should find someone that probably only you are in touch with (so these other persons do not have to spend days for answering the requests of dozens of students), someone who might possibly have a different background (which, depending on the task, might be desirable), and at the same time someone who you can reasonably ask for such a favour without coming across as too demanding.
In these examples, the exemplary nature of the mentioned roles is usually understood; at least, I have yet to see a student who would truly respond to the first (w.l.o.g.) request: "Ok. But I can't have my thesis proofread because I don't have a girlfriend/boyfriend." Of course, it's just an example of a single person who might or might not exist or be available.
The request by your professor, in contrast, to ask "dozens of family members", seems a bit extreme in comparison, but as a bottom line, you should still try to find out whether it wasn't just an example.
Or can I provide obviously fake data?
This, in contrast, might be counterproductive. You already wrote you were going to inform your professor if you do so, but better do this earlier than later. In most situations that I can think of, using an arbitrary group of real people as a sample for something is a closer match to one's real family members than making up that data.
The issue I'm seeing become apparent when considering the possible pedagogical goals of the assignment:
- The professor wants to point out a phenomenon that typically appears in data from real people. In this case, fake data will probably not exhibit the respective traits and thus will be worthless in this respect.
- The professor wants you to get the experience of interviewing real people. Obviously, this experience is not gained from producing artificial data.
In contrast, the following education achievement that you might be reaching is probably not aimed for:
- The professor wants you to practice ways to create a realistic set of artificial data. If that were the task, the assignment would have asked you to generate artificial data right away.
Therefore, my two suggestions are:
- Asking another group of people rather than your family members should be accepted by the professor. You may want to ask the professor, even though personally, I might even do so without commenting on it.
- Producing fake data, even when known to the professor, might be counterproductive to the goals of the assignment, and therefore should definitely first be discussed.