I am building a basic app for a research project. Basically, we want to see if brain surgery alters behavior based on user's facebook posts and interactions. In other words, we are trying to read all wall posts from specific users.
My initial ideas was this: As long as the researcher is friend's with the subject, I can call https://graph.facebook.com/UID/posts and https://graph.facebook.com/UID/feed. A combination of those two should give me all relevant posts.
This works perfectly for some users, but for others, I'm only getting some random posts while missing many others. For some users, I'm not getting anything at all. I cannot find any pattern as to when posts are shown and when not. Does anyone have an idea what the problem could be and how to solve it?
I'm using the read_stream permission.