in your study site will depend on whether you have established social ties there, how accessible or remote your study site is, and the availability of and access to technology (phones, Internet, etc.) at the site. Sometimes a small pilot study is useful to ensure your approach is acquiring the necessary data and is not confusing to those doing the collection or to those responding to questions. Pilot testing the analysis can also help ensure that the data can be analyzed as expected.
Of course, it is important to collect the proper information from each location, respondent, or unit of analysis in your study. This information is commonly referred to as a variable. What is a variable? A variable can be defined as a domain of attributes that relate to a particular concept. For example, the variable gender might be defined as the three attributes male, female, or other. So what is an attribute? An attribute is a characteristic that is associated with a particular object or person. The following questions might help you define the concepts to be used in your study:
Questions about data
The questions in this section relate to the data collection portion of your project. Once again, it would benefit you to answer these questions prior to going into the field. This information should be available from government agencies (local, state, county, federal) that have responsibility for the area that includes your study site (figure 2.11). In addition, contacting private businesses or local interest groups may turn up even more of the information you require. As mentioned earlier, one of the keys to successfully using GIS is to think innovatively and seek creative avenues to find the data that you might need for your study. Although you may want to simply search the Internet for agency and organizational websites to get all the data you need, this process will rarely provide anything close to a complete list of the data that are actually available. More likely, you will need to make direct contact with the appropriate people at each agency or organization to answer these questions. Because collecting and developing quality datasets is time consuming and expensive, some people will be reluctant to give their data to you. Therefore, it is often worthwhile to have something to offer in exchange for data. Data trades, access to related data to be developed during the study, or access to the final report results are all valuable offers you can make to those who assist you. When contemplating the use of GIS for any particular study, some items to consider include the following:
Figure 2.11 An example of a dataset obtained in table format. US Census.
Assuming that you can find and get access to data that will be appropriate to your study, locating useful data, especially if they are already in a GIS format, will be well worth the effort. Even if you find that none of the required data already exist and are available, that is still important information in planning your study. Knowing what you will need to collect and input yourself is important in adequately budgeting both time and money for your study.
Questions about location
The following are questions you should ask about your geographic location. These questions may appear basic, but they will help you gather information that is useful for integrating a GIS into your project. It is important to answer these questions before data collection so that you can arrange the categories and measurement devices for your project. Furthermore, thinking about the answers to these questions will help you identify important characteristics of your study location and will further assist you in the data collection process because you will have already established those aspects of your location that are important and determined which types of data variables you require. These issues are discussed in detail in later chapters. When evaluating the geographic aspects of your study, valuable considerations might include the following: