Mitchell Chapter 1:
This chapter helps highlight some of the basics to begin getting into GIS software and digital mapping in general. It starts out by guiding the reader through the process of using GIS to create a map by first understanding the data that will be used to create the map. Next, you have to choose a method to present the data based on the purpose of creating the map in the first place. The data must then be processed through GIS software to be displayed as a map, which can be tweaked by the creator in order to display the information in the most appropriate way for the situation. This chapter also goes into detail about several important terms related to GIS. Geographic features are map items that can be described as either discrete (definitely occurring or not occurring in a given position) or continuous (intensity of occurrence varies based on position). Another important term described in this chapter are the two different ways of representing geographic features in GIS, which are vector and raster. Vector models describe features on a map using x,y coordinates and connecting them with lines and can be used to show the location of specific events. Raster models were a bit harder for me to understand, although it seems they use a grid-like pattern of cells to describe an area and use different layers of this area to show where events have occurred. Overall I thought this chapter provided a lot of useful information to get started with GIS, although I would also say that the wording was very technical and difficult to understand at times. The pictures and figures that were provided helped make some of the terms and ideas easier to understand, although I also had trouble figuring out what was being represented at times.
Mitchell Chapter 2: This chapter outlines the reasons for creating maps and how they can be useful to ascertain patterns in data, as well as providing information on how to create maps that are easier to understand. This information proves useful in certain career fields such as police, ecology, and urban planning, although there are applications in almost every field. This chapter also discusses the ways to properly create maps in a way such that the level of detail included is appropriate for the topic being discussed/the purpose of the map. The example given in the book is a city council meeting where the location of heavy industry in relation to high density housing (requires precise detail) versus a meeting on overall zoning patterns in the city (requires significantly less detail). Also included in this chapter is how to map by types and categories. To map by types, the topic of the map is first determined (such as crimes) and each subset of the overall topic is given its own designation with a specific symbol or color. To map by categories, features of the map are also depicted with different symbols, although categorial maps typically offer the viewer a greater understanding of how a system works. In the case of road maps, the viewer can discern the general function of the different types of roads based on their location in relation to other roads or buildings if provided. A piece of information I found useful in this chapter was the small section about including reference features in maps in order to appeal to a broader audience. The author suggests using these features so that the viewer can understand the locations of map items easier. I thought this chapter included its information in a more digestible way compared to the previous chapter and I was able to understand the concepts presented easier.
Mitchell Chapter 3: This chapter was dense with information I found interesting and useful. A key concept in this chapter is the idea of “most and least” – information on a map that shows where the most and least of an item occurs. I think that this concept will appear often because there are many possible applications for it in different fields and scenarios. Another piece of information I thought seemed important from this chapter was the difference between creating a map for the purpose of scrutinizing data as opposed to creating a map for the purpose of presenting information to an audience in an understandable manner. Counts and amounts refer to the numerical value associated with features on a map, with counts being the actual number of features on the map and amounts being a measure of some value associated with the feature on a map such as percentages. Something that surprised me while reading (although it probably shouldn’t have) was the appearance of statistics in relation to maps. While I was reading I started to remember all the times in my high school statistics class where maps were brought up in problems. I think the portion toward the end of the chapter about creating maps will be useful when we start using GIS, particularly the part where it discusses how only necessary information should be displayed so as not to overload the viewer with redundant or useless information. I think it will be an important part of the map creation process to go back and revise our maps so that they provide the required information in a concise and focused manner. When I initially saw the pictures of the 3D maps at the end of the chapter I thought that they might be really challenging to create, but after reading I don’t think they will be as difficult as I initially assumed.