I've found that starting off broadly is a good way to go about it. Unless your interviewer is working in the same field they aren't going to know much about what you've done. Keep it simple. State the hypothesis in easy to understand terms, how you tested or are currently testing that hypothesis, and briefly sum up the results. If they ask more about it launch into the technical aspects. The key, as stated previously, is to understand what you've done and why, and to be able to articulate this clearly.