Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Concerns about Finding and Collecting Data

Datasets form the basis of GIS. These systems are sometimes referred to as being “data driven” to emphasize the importance adequate data plays in their operation. The products of a GIS are the most important contributors to its utility; the data are the chief ingredients of that product. The single message emphasized by this section is that any determination of what data are needed, and what the characteristics of those data should be, comes after a very careful look at what sorts of information products are required for specific decision making. The products, one would hope, are developed to satisfy the needs discussed in Chapter 2 and the requirements for analysis that we will take up in later chapters.

Determining what datasets are needed is not an easy process. It requires the concentrated effort of experts, from the decision makers who will use the ultimately produced information to the scientists who gather and analyze the data. The ideal order of matching data to needs is from the specification of the information product back to the data gathering—that is, in the direction opposite from the one in which the process of producing the information takes place.

The fact that a lot of already collected data exists will influence not only the process of turning those data into information but also the types of information produced. However, to allow the fact that some inappropriate data are at hand to dictate the output of a GIS reminds ...