Why are all these papers exactly 10 pages long? I've been reading papers authored by professor A's PhD students. I have read about a dozen of papers by now, and realized that all of them are exactly 10 pages long. These papers were written by different PhD students and they were published in several different venues (very good ones). Is 10 the magic number for paper-length? (at least in professor A's field, which is computer science - human computer interaction)
Most American computer science conference papers are precisely 10 pages long, because most ACM conferences have a strict 10-page limit on proceedings papers.

(ACM is the Association for Computing Machinery, the primary professional society for computer science.)