Chapter 1
The first chapter of the book by Andy Mitchell goes over the fundamentals of GIS analysis, emphasizing the importance of understanding geographic features and patterns which can be used to find relationships in the data on a map. The chapter defines key concepts like geographic patterns, which can be random, clustered, or evenly spaced, and spatial relationships such as proximity. These concepts are important when someone is looking at a map and is trying to decipher what they are looking at, where the map location is, and where it is in relation to other existing locations. He also defines key terms such as categories, ranks, counts, amounts, and ratios which are all continuous values and are used when making maps. A key takeaway for me is how GIS transforms raw data into insights by combining statistical and visual analysis. I am not a very mathematical person, so this entire concept is foreign to me, but I am interested in learning more. For example, geographic features can be categories into discrete, continuous phenomena, or data summarized by area. Discrete features can vary immensely, one example being crime locations, and are best represented using vector models. Continuous data is more suited for raster models. This chapter also explores map projections and coordinate systems. It’s interesting how the curvature of the earth needs to be taken into account, as larger projections will distort geographic attributes unlike the smaller scaled maps. This makes me wonder how GIS professionals deal with challenges posed by inconsistencies in data quality when performing large-scale analyses.
Chapter 2
Chapter two delves into why and how to map in order to make a map that makes sense. This chapter emphasizes why it is crucial to map the location of features to reveal patterns that inform decision making. An example of this is identifying areas with high crime concentrations and can affect urban planning. The chapter details the importance of clarity in map design and highlights how basic maps showing where features are can uncover important patterns. Symbols and classifications also play a key role. Mitchell states that a good rule of thumb is that no more than seven categories should be displayed on a map at once… however this can change depending on the size of the map. This chapter helped me appreciate even more how GIS has shaped everything around us. I like the real world examples provided. One important one is the police department examples. I wonder how much harder their job would be without GIS. What I thought was interesting was the importance of balancing detail and simplicity. The decision about what data to use and what background color all shape the narrative of the map.
Chapter 3
This chapter explores the importance of mapping quantities to uncover relationships and support decision making. By using counts, amounts, ratios, or ranks, GIS can add depth to geographic analysis. This chapter was very interesting to me because it combined technical explanations with real world applications to things that are important to me such as resource distribution. Visualization methods like graduated symbols, color shading, and 3D perspectives were introduced as tools for effectively communicating data. I found the section on ratio mapping compelling, as it demonstrated how averages, proportions, and densities provide meaningful comparisons across diverse regions. One interesting observation was that larder areas should not solely rely on counts but also use ratios to present a fairer analysis.
This chapter’s explanation of classifications methods, such as natural breaks and quartiles was really interesting. I am a stranger to all of these and am excited to learn more. These methods group data into classes, allowing patterns to emerge. It was interesting to compare visual examples, as they revealed how different methods tell distinct stories using the same data. This reinforced the creative aspect of GIS. This chapter deepened my appreciation for GIS, but also made me feel a little more overwhelmed. There are so many different uses for GIS and I wonder what GIS professionals decide which classification methods to use depending on the audience or goals they have. I know that this will be a useful tool in the future.