Tips for Othello Performance Comparison

[dako7]

I'm writing an essay for a Shakespeare class that compares the final 150 lines or so of Othello Act 3 Scene 3. I'm looking to answer the question: how is Iago portrayed by different actors in the final lines of Act 3, Scene 3, and what does this portrayal reveal about his relationship with Othello? I've been looking at Trevor Nunn's version of Othello with Ian McKellen as Iago, Kenneth Branagh's version, and Jonathan Miller's version with Anthony Hopkins as Othello and Bob Hoskins as Iago.
There are differences in each actor's performances, but I've never written a performance comparison essay like this before. What guidelines would you recommend I follow, and what tips would be helpful? Thanks!

[kelby_lake]

Deal with each performance in turn. Make sure that you make your opinion on it clear: how does X interpret it, what effect does this have, and is there a big similarity or difference between a choice that X makes with one that Y makes? Basically, compare and contrast.

[My2cents]

A thing you might be able to state and compare definitively are the number of lines each production has each actor speak. Very often, especially in modern productions, the lines are edited. So you might compare an old film where the actor speaks all the lines w/o omitting a syllable to a modern one which has a few lines edited/omitted or rearranged. And then you can say which is more dramatically effective, or which one you prefer and why, and so on and so forth.