Groupon Data Scientist - Local interview questions

I applied the position online. The recruiter emailed me in a couple of days and set up a phone interview in the next week. The interview started smoothly. After introducing each other's background, I got a chance to ask question. But, I didn't present my idea very well. Then we headed to the technical part. The first question was about probability and statistics. It's not a hard question. But, since I'm not a native speaker, I have difficulties in using exact terms, and I forgot the most important term behind the question - maximum likelihood. Anyway, I think it's my self who did not show the best of myself.