Chronologically is the way to go, imo (an obligatory rhyme). Simply because chronologically is the same way that the reader reads it, and the way the writer writes the piece is geared towards this. When writing an article one must ensure that each idea logically flows into, and builds upon, the ones preceding it, the author is developing his argument over the course of the whole piece in order to serve his larger strategy whereby he hopes to persuade the reader that his point of view is correct.
What you could do, however, is that you could take a device that occurs early on and jump further on in the piece to another device which builds on that idea, such an approach would be ideal for an article such as the one used in the exam last year where there was a lot of back-referencing to ideas brought up earlier in the article throughout the piece, as a form of ironic juxtaposition, which were difficult to address if the article was analysed wholly chronologically, but this is the exception not the rule.
Edit: A bit like what Nirbaan said.
Teacher28: Oh, so that's what his teacher is asking him to do. I guess that makes sense too, especially since it allows you to work more closely with the author's intent.