Personal Genteelism

Some people have asked me about using "I" in essays. Although there are some areas of scientific publication where this is (becoming) acceptable, I recommend that you avoid it for the moment, unless you have cleared it with a specific lecturer.

You should usually be able to state your position in third person. So instead of "I think the data are unreliable for the following reasons" you should say "The data are unreliable for the following reasons."

The other thing you can do is refer to yourself as "the author". I would avoid frothy phrases like "the present author of this communication" because you sound like a dick. Keep it simple.