Is a question ever so simple that answering isn't considered necessary because the answer is readily available, e.g. via a web search?
This comment and associated question provides the background for asking this.
No a question is never so simple to best be left to a google search. Most of the questions posted here so far are also covered on the web, if not all of them. The site is supposed to be a collection of all homebrew questions and a ranking of the valid answers as voted by the community. When you do a web search for an answer you have no idea to what level of confidence you should accept that answer. StackExchange lets you see exactly what a community of like minded people think of an answer.
I disagree with this and I think there should be a 'general reference' close topic added. This is discussed here: http://blog.stackoverflow.com/2011/02/are-some-questions-too-simple/
It's implemented on a few other stackexchange sites with this explanation:
I saw it recently on english.stackexchange.com
There are questions that are too simple. For example, "What is malt?". This is homebrewing related, but the answer is in any dictionary, basic text, encyclopedia, wikipedia, etc. If you don't know what malt is, you probably should look it up elsewhere, because you will have a hard time understanding just about anything on the site without this knowledge.
Here's an example of question that is too simple on the site, and I'd argue that it brings down the quality of the site:
No one answered this question, so the asker copied and pasted an answer to his own question from wikipedia (with quotes and attribution). I would say there was some value to having it on the site if it were something where an expert could make a valuable contribution to the subject, but in a question like this, how is that possible?
It's like asking "What is addition? How does it work?" on math.stackexchange.com.
Therefore, I think a close option should be added for reason of being too basic.
The only worry is that it is tricky one to apply, because there is a fine line between something like "What is mashing?" which I think would be too basic and something like "What is conversion?" which I also think is too basic, but has triggered some interest.
An alternative might be to flag posts like this as community wiki.
No, If you don't want to answer a simple question then you are free to leave it, but let it ride. Someone else probably will answer it, so leave simple questions to junior members to answer and grow reputation. Intervene if the question is poorly written, answers are incorrect, duplicate question ect ect.