14 DAY TRIAL // Let's not beat around the bush and set things straight. Yahoo Answers is not the address you want to type in, when you need to find something out. Eventually, you could use it whenever you want to see some interesting opinions on whatever it is that interests you, or if you want to see just how far spirits can inflame, before it gets down to swearing.
Yahoo Answers was and still is a way to submit your question to every potential visitor of the site, and while some very smart ones are bound to see it invariably, some less intelligent ones are also sure to check it out. The catch is that you won't know which is which until you see the answers. And guess what, the people you want to answer your question are usually not the ones that really do, they too have questions for others, and so on, and rarely have the time for yours.
Children doing their homework might benefit a lot from this kind of service that Yahoo provides; the one downside to it is that besides cheating by asking others to do their part (which is wrong, by the way), they might come across somebody who knows even more on the topic than themselves and because of that blow it with the assignment. Serves them right for wanting to cheat, teachers might say.
The trouble with the service is that sources are so rarely posted that it is amazing if you find two in the same session. And with the known trouble that the youth have, to differentiate fact from opinion, it grows to be a problem.
The similar sites that offer the same services are, thus, a lot more trustworthy. Take Wikipedia, for example. It is also user-contribution-friendly, but it does have included several tools to help surfers identify potentially problematic sources of information. Tools are good, opinions are bad. At least in this case.