This is a proposal for a feature request.
The proposal
Improve a tag description to include a search expression. This search expression is evaluated against each new question posted, to evaluate if the tag is relevant for the new question.
Improve the user interface so that, when posting a new question, the user is given a list of tags detected as "relevant". The user then should accept or decline each proposed tags (mandatory) be able to add more tags if needed (optional), before being able to proceed to the final "POST MY QUESTION" button.
Optional proposal
To avoid presenting too many tags to accept or decline, limit the proposed tags to a maximum number (say, 10), and propose the tags that are the most selective first. The "selectivity" of a tag is computed based on the number of questions that match the search expression (or have the tag), divided by the total number of questions.
Why it is needed
I think is it not realistic to expect users, especially first time users, to know the definition, not to mention existence, or every tags that are relevant to the question posted. As a result, questions are most of the time not properly tagged.
Using correct tags should significantly increase: - the user awareness of these tags, - the likelihood the question will be even looked at, by people monitoring only certain tags (like me),
How it can improve the community
This feature would, in my opinion: - increase the quality of questions - educate first time users more effectively - reduce the time spent by the community maintaining tags - increase the probability a user will find a tag wiki and the associated documentation - should the tag wiki actually contain pointers to FAQ, this can even improve the probability a poster will find the answer to his question even before hitting the final post button, preventing the question to even enter the system.
Examples:
Tag [mysql-error-1064] is expected to be more selective than tag [mysql]
Tag [mysql-error-1064] search expression can be:
"You have an error in your SQL syntax" +error +1064
If you compare the number of posts with this expression (1759), compared to the number of posts with the tag (695), the numbers just show the tag is not effective. Note also that 695 is "high", because I started earlier to manually add the mysql-error-1064 tag, before realizing it is hopeless.
Another example: Tag [shift-reduce-conflict] : 36 posts
Expression shift reduce conflict 3665 posts
The effectiveness of this tag is 1/100.
I believe this principle can be very effective for stackoverflow, as users will search for solutions to an "error", and errors are easy to search (specific message, function, number, etc).
P.S.
I have found (actually, the system found them when posting this) some similar questions:
When asking a question, could the page suggest relevant tags?
Automatically determine tags while writing a question
but I don't think this should be closed as a duplicate.
What is new in this proposal that I have not found elsewhere is the idea to improve the tag description to compute relevance.
tagstag on a question about tags? :-)