A lot has been discussed about this subject on Q/A sites, like the ones on StackExchange.com sites.
Basically (quoted from SO):
Using the title to ask a question (a good, not retoric one) is going to give the reader as much context in as short a space as possible. A good question is going to let the reader know what he is going to read, and in this case, let the answerers know what end-state you desire.
Let's take your first example, "Fooing a bar". Although short, it lacks context. There's nothing in the question that indicates what sort of answer that could be. Possible actual questions include:
- Philosophy: Is it wise to foo a bar?
- Advice: When should I foo a bar but baz a bar?
- Mechanics: How do I foo a bar?
- Possibility: Can I foo a bar?
- Comparison: How many different ways can I foo a bar?
- Survey: How do you foo a bar?
Those extra words aren't just sitting there doing nothing. Each one of those is a different question with a different answer and a potentially different audience. They are directing the answer and informing the reader. Choosing the right question is the key to getting the answer that you need.
end of quote
Here are some related questions with answers from StackOverflow site talking about the subject.
Sorry for taking SO as an example, but as for today I consider it to be the best Q/A site. Also on the old forum it clearly states that this new site will follow SO guidelines.
That's the question we needed: +1 :)
Indeed. Although 'How to use the title field' is not a question, so it should not have a question mark ;)