Correct use of “comprise” is one of my hobby-horses; I recently found a couple examples of it being used correctly, so I decided it’s time to have a repeat lesson.
Shall I tell you why people get “comprise” wrong? Because they want to sound educated. In other words, they’re being pretentious. It’s the same thing that leads people to say “prior” when they mean “before,” and Latinize the plural of “process” into “processese.” Artificial fancy usages are pretentiousisms. “Is composed of” sounds so mundane, they have to class it up with a fancier word. Trouble is, they get it wrong.
“Comprise” means “is composed of,” which is a passive construction. You want to avoid using the passive when you can, so “comprise” is a handy alternative.
A hybrid eclipse comprises a total solar eclipse and an ‘annular eclipse’, depending on an observer’s viewing location on Earth.
Four of the five remaining Santa Cruz cypress habitats are now parklands or ecological reserves. The population comprises a healthy 33,000 trees or more, so the fws [Fish and Wildlife Service] has proposed reclassifying the species as merely “threatened.”
You can find the first quote at http://www.spaceref.com/news/viewpr.html?pid=41862 and the second quote at http://www.world-science.net.
Rule of thumb: Start with the single, big thing, then comprise, then more than one smaller thing. So, Hybrid eclipse comprises total and annular. Now you do the second one for practice. Be clear, not pretentious.