1) How did this exercise help you build empathy with prospective users? 
We collected prospective users’ information such as user interests, needs, motivations, frustrations and so on by reading the users’ statements in interview transcripts. According to the interview, we can observed that interviewees always tell you their interests and requirement indirectly, we need to analyze their statements and try to step into the shoes of the prospective users, and then we might see the situation from their perspective and understand what’s their interests, needs and motivations or so. For example, according to this  part of the interview transcripts:
“It’s just so much easier when somebody can give you a few pointers to get started. I tend to travel in such a way that I have a couple destinations that I’d like to go to and maybe they helped me figure out”
We can find that this interviewee needs some recommendations from the local people.
2) How did the clustering of information help you to understand user needs?
Because only one user’s needs cannot represent the needs of majority of people. Thus user’s needs that we collected from interview transcripts need be clustered, and we can find that those different user may have some similar needs and interests. And then we can pick up those similarity to summarize the needs of the group of people. Therefore, clustering of information help me to understand common user needs and we can better solve those people’s problems or requirements according to the needs.
3) What was difficult or challenging with the technique? How would you do it better next time?
Because of time limitation, almost of our group members haven’t finished the reading of the transcripts, and we have not collected too much information about users’ needs, interests, motivations and frustrations. Thus the similarity which we found this not enough. Next time, we should deeply understand the interview transcripts, and collected more user’s data individual, thus we can summarize more useful common user needs.