You are considering writing about the following topics and issuers: 1)school uniforms 2.)length of school days 3)random backpack searches 4)cutting extracurricular activities and 5)online schooling. which guidelines should you follow to you choose an appropriate topic

You should choose whichever issue is most prominent, then research to find the topic with the most reliable information. from there, you can build your base on that solid information. it has to be facts or a legitimatized opinion, otherwise you can't easily defend your position on said topic. make sure your opinion is well founded. you should also be interested in the topic, otherwise your attention will slip. 

Depending on what the circumstance is in that you'd be choosing an appropriate topic, if its for research purpose's in order that you'd be writing an essay then these may be a few guidelines that would help.
1) Am I well informed upon this topic and am I confident in what I have to say about it?
2) Is it backed up by statistics that I may need for better information that I can provide to others?
3) What makes me sure that I can write well enough about it? Because I am part of it, because I read about it, or because I experienced it?

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