Why do some people put the source of info in the answer and some don't. I always prefer to know where the?

Question

answer came from so it can be checked out. There are lots of UK people don't do it.

Answer 1

Certainly there are times when the answer is based on their own knowledge, not something from a website.  Sometimes we may have learned something from a website at some point in time, but don't remember the site.  I agree that if someone just researched it to help with an answer, then a short synopsis should be in the answer, then the link provided so the asker (and others with interest) could read for themselves.  As to why some don't do it... probably just don't think to do it.  Personally, If I've gotten the information from a website, I'd rather give minimal information here, then provide the link, than copy & paste and possible leave something important out.