You could've read some papers on the topic for example. (I'm answering this because it is after all in the stupid questions thread)

More "Stupid" Questions

by NancyLebovitz 1 min read31st Jul 2013498 comments

14


This is a thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. The previous "stupid" questions thread went to over 800 comments in two and a half weeks, so I think it's time for a new one.