How do I prevent myself slipping into narrative during analysis?

In order to maintain sophisticated analysis instead of a description of events it is important to keep asking yourself questions as you go along. For instance, if you're meant to evaluate the importance of an event, ask yourself: why this event was/wasn't important? Was it's impact short or long-term? Did another event perhaps affect more of the population than the one stated in the question? By pulling the 'importance' of this event apart you're making sure that you're offering analysis as oppose to if you only described what the event did without a comparison or detailed criticism. It's easy to get narrative and analysis mixed up, but as long as you keep asking yourself questions after each of your points you'll be sure not to slip into description.