3. Research is Iterative

pros and cons is a bad keyword option

Iterative. Iterative means repeated. The research process often includes repetition, and for very good reason.

Many people want to investigate all sides of an issue when they do research.  Adding the phrase "pros and cons" is not a very effective way to accomplish this.

There are many useful articles that focus in on very particular, specific impacts, like the academic benefits of school uniforms, or the constitutional problems with school uniform policies. 

Instead of trying to get all sides of the story with one search, think about the different types of benefits or costs people are talking about and plan to do several related searches to make sure you are getting multiple perspectives on your topic.