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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:

Do GIS data exist in any form for your study site?

If not, what sort of data exist that might be GIS compatible?

Do you have access to these data, and if so, under what conditions?

What was the original purpose for which the data were collected?

What sorts of variable attributes are included in the dataset that you are interested in examining?

How old are the data? Were they collected at only one time, or are they longitudinal?

What metadata exist for these data?

Has any type of accuracy assessment been completed, or have these data been ground truthed?

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.