Selecting the appropriate data for your GIS project is an important first step. This worksheet is designed to help you think through what you are trying to accomplish and to clarify your data needs. Working through this sheet will help the Libraries staff give you the data you need in the most efficient manner. You can also work through this list and leave it for the GIS Assistant (firstname.lastname@example.org), who will contact you to make an appointment to retrieve your data.
- What do you want to do with the data? Are you creating maps or performing analyses? Are you mapping streets and bike paths in Seattle, or are you analyzing distances between the two? Do you need socioeconomic or demographic data, or physical features? What is the end result you are trying to reach? Knowing where you want to go will help you determine what you need to get there.
- What are the specific geographic features you need? Even for a specific feature like "streets," you may need to describe how you want them represented (centerlines, double-lined streets, connected routes, points), the level of detail (all streets, major highways), the level of generalization or positional accuracy (e.g., major highways at a "local" scale, such as 1:24,000, or at a "national" scale, such as 1:3,000,000).
- What attributes of those features do you need? For streets, you may need none, some, or all of the following attributes: street name, route number, road class, road surface class, address ranges, traffic volume, under or overpass.
- What is the geographic extent of your area of interest? Do you need data for the State of Washington, Olympic Peninsula, Puget Sound area, City of Seattle, Capitol Hill? Census tract, block group, ZIP code?
- Are parameters such as scale, datum, projection, and coordinate system important to your application? This can be especially important when combining data from different sources.
Other things to consider:
- Metadata. Metadata is data about the data – it provides information about data quality, accuracy, projection, lineage, etc., and helps you determine fitness for use. Just as you wouldn't use an unattributed quote in a report, you don't want to use unverified data in a project.
- File size. Many digital data sets are several megabytes in size, and will require sufficient storage space. Does your UW account have room for that data? Do you know how to request more room? Do you have access to another server that will accommodate your files?
- Time. Some files you request may take time to retrieve or generate. Please give staff ample notice to get your data to you. Many files will be delivered to you within 48 hours of your request (not including weekends), with most being delivered much faster.
- Your experience. Are you performing analyses you've never done before? Are you new to the software? The Libraries can provide you with data and brief (approximately one-hour) consultations on your data or projects. It's a good idea to have a manual on-hand and to utilize the expertise of your department, if appropriate.
- Your region of study. The UW Libraries' collection of digital geospatial data concentrates on the Seattle, Puget Sound, and State of Washington areas. Data for the rest of the United States and the world is also collected, but local information is more extensive.
Examples of data themes:
- Land Use/Land Cover
- Sensitive Areas
- Street Networks