Research Assignment

I have decided to focus on the issue of grammar education in public schools. I am interested in several aspects of this issue and am still kind of deciding in which way I should go. For instance, does the teaching of grammar help students write (or even speak) better? If there are any benefits to learning the mechanics of the language in your everyday life, at what point in a student's education should this be tackled? (ie elementary or highschool) Also, I am curious if perhaps the grammar itself has become antiquated and therefore not very useful in the actual workplace. I am thinking of the rules concerning gerunds and thier subjects or pronouns in the objective case. If no one knows these rules, should they be taught at all?
The final thing I have pondered is the actual method used in teaching grammar: prescriptive or descriptive? I think that I have kind of already decided that the prescriptive method of rote memorization and correctness is basically ineffectual so I guess my question would concern the descriptive method and how it would be implemented.