{"id":7303,"date":"2026-09-04T10:48:53","date_gmt":"2026-09-04T15:48:53","guid":{"rendered":"https:\/\/sites.owu.edu\/geog-291\/?p=7303"},"modified":"2026-09-04T10:48:53","modified_gmt":"2026-09-04T15:48:53","slug":"redman-week-2","status":"publish","type":"post","link":"https:\/\/sites.owu.edu\/geog-291\/2026\/09\/04\/redman-week-2\/","title":{"rendered":"Redman week 2"},"content":{"rendered":"

Chapter 1:<\/span><\/p>\n

The chapter starts by explaining that GIS analysis is a process for looking at geographic patterns in data and relationships between features. The data may either be simple or complex. The process for performing an analysis includes five steps. The first step is to frame a question. To analyze something, you need to know the information that you want to find, and this requires forming a question. The second step is to understand the data to be able to determine what method to use. Third is choosing the method. Some methods are less time consuming than others, but only provide a basic understanding, and the methods that take longer produce more in-depth results. The fourth step in processing data and performing the steps in GIS. Finally, the results will be produced as a map, chart, or something similar.\u00a0<\/span><\/p>\n

Understanding geographic features is an important part of GIS. There are three different types of features that can be used. Discrete features are used for discrete locations and lines, and location is able to be pinpointed. Continuous phenomena are precipitation or temperature and can be found or measured anywhere. It blankets the entire area of mapping. Features summarized by area represent density of features within boundaries.<\/span><\/p>\n

There are two ways to represent geographic features. The first is a vector model, which includes features (discrete locations, events, lines, and areas). The second model is a raster, which is a matrix of cells. It is important to have the same map projection and coordinate systems to ensure accurate results.\u00a0<\/span><\/p>\n

It is important to understand geographic attributes to determine the type of analysis you want to do. There are five attributes. Categories are represented by numeric codes or text. Ranks are used for when direct measures are difficult. Ranks are relative, so it is not exact. Counts and amounts show total numbers. Ratios show the relationship between two categories. Categories and ranks are continuous, counts, amounts, and ratios are not.<\/span><\/p>\n

Working with data tables is important for GIS analysis. Three common operations are selecting, calculating, and summarizing.<\/span><\/p>\n

Chapter 2:\u00a0<\/span><\/p>\n

This chapter starts with explaining that mapping where things are can show where action is needed. This can eventually show causes for certain patterns, such as a concentrated area for crime rate.\u00a0<\/span><\/p>\n

In order to decide what to map, you need to know the information that you are trying to gain from the map, and how the map will be used. The information needed for a map can differ depending on the end goal. Some maps are used to determine a concentration of something, others can be used for discreet locations. Determining how the map will be used can be determined by the audience and issue being addressed.\u00a0<\/span><\/p>\n

Preparing the data requires assigning geographic coordinates and assigning category values.\u00a0<\/span><\/p>\n

To actually make the map, you put the information into GIS. the features can either be displayed in a layer as a single type or categories. In a single type, only one symbol is used. This can show patterns. Mapping by category uses multiple symbols and can provide a more detailed understanding. This allows for displaying features by type, how many categories there are, which features are mapped, the map scale, how categories are grouped, and which symbols are used. It also allows for reference features such as major roads\/highways and landmarks.\u00a0<\/span><\/p>\n

If the map produced presents the information clearly, patterns in the data can be seen. If it is a single category, features can be clustered, uniform, or randomly distributed. Patterns can begin to provide explanations for why things are where they are. While this can provide a visual example, to determine if the patterns are significant, statistics are required to quantify the relationships between features.<\/span><\/p>\n

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Chapter 3:<\/span><\/p>\n

In GIS, people map the most and least to see the relationship between places. Mapping features based on quantities can provide extra information in concentration. For this mapping. You need to map the patterns of features with similar values.\u00a0<\/span><\/p>\n

Knowing the types of features that you are mapping is important to know how to present the quantities to see patterns on the map. This can include discrete features, continuous phenomena, or data summarized by area.\u00a0<\/span><\/p>\n

When making a map, the purpose of the map is important to know how to present the information. To map the most and least, understanding quantities is important to be able to assign features.<\/span><\/p>\n

Once the quantities are determined, they can be represented by assigning each value its own symbol, or grouping the values into classes. Mapping quantities requires a balance between accuracy and being able to be able to see patterns on a map by generalization of values. Counts, amounts, and ratios are grouped into classes.\u00a0<\/span><\/p>\n

Mapping individual values presents an accurate picture of the data, but may make it harder to read the map. Classes can make the map much easier to read. For making classes, they can be created manually or by using a standard classification scheme. Classification schemes include: natural breaks, quantile, equal interval, and standard deviation. It is important to be able to choose the best one for the information you have.\u00a0<\/span><\/p>\n

Once the data has been effectively classified, the next step is making the map. Make sure that only important data is used to ensure easy comprehension by readers. GIS provides these options for creating maps to show quantities: graduated symbols, graduated colors, charts, contours, and 3D perspective views.\u00a0<\/span><\/p>\n