Reputation created through writings, legend, exhibitions, books, films and so on. On one hand, I think that museums are constantly having to play "catch-up" and also are trying to follow current trends, not wanting to look foolish by displaying works by someone whom the public or critics might ultimately reject as untenable or uninteresting. From knowing some people who have worked for museums it often comes down to their own tastes and interests when it comes to purchasing works. Ultimately they answer to a board of members and directors. I was recently asked by someone who was a member of a voting board about what I would like to see in a certain modern museum's collection and I said without hesitation: "sculpture".