information component of GIS relates to the database aspect of the software. Databases are specialized software programs designed for storing, organizing, and retrieving information. GIS software packages can read or directly interact with data from almost any data management and analysis software. Some data translation may be necessary to facilitate the movement of an existing research database into a GIS software package. Many of the fundamental baseline datasets you might need to answer a question are already available in GIS-ready formats.
In particular, data from the US Census as well as many state- and local-level datasets are available through online sources or via a visit to the appropriate government office. Numerous university sources also provide GIS-ready data, as do a variety of private firms. Many of the data are freely accessible, including a wide range of spatial data from government agencies and other organizations. Additionally, a number of commercial databases are available for purchase. Such databases typically compile specialty data that are in some cases not available through other sources. Commercial data may be updated more frequently and may already be compatible with your GIS software.
The decision whether to use free or commercial data most often comes down to your needs and experience. Esri provides users access to a wide array of both free and commercial datasets designed to operate seamlessly with ArcGIS. Many other third-party providers also sell a wide range of economic, infrastructure, business, and social data types. Commercial data are reviewed for quality and presented in formats that are compatible with popular GIS software applications. Many free sources are similarly prepared, whereas others may require more effort and manipulation to make them compatible with a particular GIS package. Choosing your data source may simply be dependent on your budget. If you do not have the resources to purchase data or to collect your own, new data, you may need to explore free options. Of course, if you use free data, there could be a trade-off in the time it takes to prepare the data for use in your analysis, or the necessary data may simply not be available.
Of course, you can also use your own data, whether collected via survey, interview, observation, or almost any other means. In fact, so long as you intend the data to end up in a computer in digital form, regardless of the particular software involved, it will be accessible to a GIS. In fact, with a little foresight, perhaps through one or two additional questions or notations on the data sheet, you can collect data in a way that facilitates easy incorporation into GIS. These additional data can take the form of either real or conceptual locational information tied to a basemap that you choose (figure 2.6). Thus, the informational aspect of GIS is the easy part because almost everyone working in social sciences is already familiar with the process of collecting and coding data. Most are also familiar with entering data into a computer for analysis.
Figure 2.6 Esri provides a wide range of basemaps through its online map services. Some basemaps may require special licensing. Similar basemaps can be obtained from government agencies and other commercial data providers. Esri.
Extending the I
Making information more accessible to GIS requires upfront organization and structure of data storage as well as data coding and formatting. These tasks are not unique to GIS; rather, they are essential considerations for all data collection and analysis. Computers and GIS provide additional storage opportunities. Multimedia capabilities of the computer allow you to link photographs, sound bites, movie files, and scanned information, providing significant opportunity for raw data preservation and thus maintaining complete, detailed information.
For example, you could record a key informant interview or oral history on tape in its entirety, or you could record a traditional dance on video. (A key informant is an individual who is knowledgeable about the particular issue or topic under study. An oral history is a qualitative research method in which a researcher gathers individuals’ stories and histories associated with a particular place, event, or issue.) You can convert these records into sound and video computer data files and link them to a GIS map, as discussed in chapter 6. When a user clicks on the location associated with a video or sound file on the GIS map, the complete recording becomes available.
Data coded or summarized from open-ended surveys or interviews for purposes of analysis are simultaneously available in their entirety to a researcher who may opt for a different coding scheme or analysis at a later time. To code data means to assign a meaningful symbolic numbering system to represent the answers in the data. For example, researchers collecting answers using a rating scale of 1 to 5 may reserve an additional code to represent questions that the respondent skipped, 0 or 99 being the most commonly used codes for this purpose.
Thus, beyond the many analytical and data presentational benefits we explore in this text, the GIS can store a variety of digital datasets collected during a particular study. If these data can be maintained in raw form, they can be used in new and different analyses at a later time. If you consider how your data can be used in the future when you build your library of GIS datasets, you can greatly extend the life and utility of any individual dataset.
The S in GIS
The system necessary to carry out development and analysis in GIS includes a variety of hardware and software components, in addition to people who can make these components work. Most academic institutions and government agencies, and many private consultants, may have these capabilities. The cost and training required to build a GIS from the ground up varies greatly. What is important for you to consider are the trade-offs between doing the GIS work on your own versus turning over aspects to a more highly trained GIS analyst. Regardless of what you decide to do, you need to ensure that everyone working on the GIS understands the data structure and format needed to achieve compatibility with minimum difficulty.
Difficulties with the S
GIS were largely developed with traditional geography in mind. Since the initial development of GIS, the use and capabilities of GIS have expanded across a variety of disciplines and applications in both the public and private sectors. However, these systems are limited by the map data model, consisting of points, lines, and polygons. This model assumes that all data can be linked to a specific, discrete location and that lines can be drawn to explicitly delineate the boundaries between data categories. Of course, many datasets are not so clearly defined, especially those collecting social science data, which tend to be less geographically specific, either because the data must be degraded to protect privacy or because social science research typically involves analyzing conceptual maps as opposed to geographic maps.
Although there have been efforts to develop fuzzy GIS systems that allow locations and boundaries to be less definite, these systems are not yet available in the mainstream. Therefore, the existing GIS data models do not necessarily fit the analysis being conducted, and you may be forced to come up with a creative solution to make nondiscrete data fit into a discrete data model. One caution is that it is easy to allow the capabilities of the software to dictate the analysis you carry out, or conversely, the analysis you never attempt. This is one reason why researchers in some areas of social science have taken longer to integrate GIS technology into their research than researchers in the natural sciences (who have been using GIS for about fifty years). Nonetheless, GIS began to find its niche in social science applications soon after its early development, most notably as a tool for collecting, storing, and analyzing US Census data, beginning with the 1970 US Census.
Those early years of GIS focused on natural resources for two simple reasons. First, natural resource managers in Canada, with vast amounts of information to map, originated GIS technology in the