The presentation by Prof.yimi was very clear and straightforward. The presentation showed us how a survey should be formed, and what is the major problem that we might encounter when we are doing our own survey.  The presentation also made me realize that questions in the survey should be asked in a certain order so people feel comfortable to answer the survey question. When Pro. Yimi said that the most difficult part is to find people to take surveys, i was wondering if there are any websites or organizations that could provide such a service which could find people to take the survey. However, I realized that we need students on our campus to take the survey, not other schools. Hence, I think it would be a good idea if the survey is asking some general question or market investigation toward society.

I feel pretty familiar with chapter 2, since it talks about the map theory that I learned before from discrete mathematics. A network is a key thing to understand some complex concept. The network can show the relationship between each node, these nodes can represent anything. In discrete mathematics, these nodes are denoted as vertices, and lines between them are denoted as edges. If the edge has direction, then it should be called a vector. The vector could have different meanings, if the map is representing a certain relationship, for example, the kinship.  Furthermore, the network could also be used to present the airline, for each line, or edges, we can show their price as weight in the map.  By doing so, some information will be very easy to extract, for example, the cheapest airline to the destination etc. However, when the scale is too large, too many vertices will also become a problem. If the degree for each vertex is a pretty event, then it must have many edges that connect with each other, the map will be messy and hard to read.