Q1. Our topic is about the supermarket, we got 4 different interview sheets, and 2 of them are pretty similar as we both at the same age group and same education background etc. Because two of our group are full time worker and full time students, their experience are a little bit  different. So I think in our group there is not enough commonality to form a coherent persona, i think a typical persona should requires at least 3 in 4 people got the similarities.

Q2. From my perspective, the sample was too small, 4 is not enough to form a coherent persona. A large group of sample would make it better.