Not all GIS software is created equal. When deciding on which GIS software to purchase, there are several things you should look for.
#1 Purpose
What will you be using the software for?
Think about the application area first, such as spatial health analysis, climate change, transportation, crime, natural resources, urban planning, etc.
Now consider the questions you’ll be addressing in your application area. These can be thought of as the four W’s: What, Where, When, and Why.
You might be working in forestry and need to inventory forest stands and their location. In this situation, you need a GIS software that can readily handle the What and Where questions:
- (What) Identify the different types and statuses of woodlands
- (Where) Locate them for management purposes
For spatial health analysis, you may be concerned about disease prevention and assessing whether interventions (such as a prostate cancer screening program) are effective. You might then be concerned with all four W’s: where is prostate cancer incidence (where and what) increasing/decreasing through time (when), and is that change attributable to changes in our screening programs (why)?
In a public health GIS, you may want to visualize changes in prostate cancer late-stage diagnosis for both white and black males. Above, we see maps of prostate cancer late-stage diagnosis through time for both white males and black males. Red colors indicate a high level of late-stage diagnosis.
Here a new screening tool, prostate-specific antigen, was deployed across the state, leading to a decrease in late-stage diagnosis. Can you see when this effect began to be noticed? Are there any differences in the incidence of late-stage diagnosis between white and black males by location and through time? This demonstrates how maps can assess policy impacts and health disparities. Map is courtesy of Dr. Pierre Goovaerts.
#2 Usability
How easy to use does the software need to be? Some products are highly capable, but this large roster of functionality requires training on how to use it.
Some deployments require a trained expert with an MS or equivalent in GIS or geographic information science. Other software solutions include a subset of those in more complicated GIS software but are easier to learn and use. Think about what the software will be doing and then consider the complement of GIS functions you need to accomplish that purpose.
#3 Cost and budget
The overall cost of a GIS software can be an overriding consideration. Cost components for GIS usually include the software itself, often an annual subscription, data acquisition costs to purchase base maps and other data, and operating costs. Operating costs can be almost negligible for more focused solutions that do not require trained experts or range into hundreds of thousands annually to maintain a ‘GIS jockey” on staff.
#4 Level of Customization
GIS software is required to generate maps for visualizing geography and relationships among the mapped data.
These usually are customizable, with control over the base layer (background), how map features like buildings or roads are displayed, and the schemas used to classify data values for display.
For example, choropleth maps color areas (such as census districts and counties) based on associated data values, such as disease rates. In these instances, there will be N disease rate values, where N is the number of counties being analyzed. These can be color-coded using a continuous color scheme (e.g. gentle gradations in color intensity from blue, for low disease rates, to red for high disease rates). But the disease rates might also be classified, using specific intervals of equal range (e.g. 0 to 1.5 cases per thousand, 1.5 to 3 cases per thousand and so on). They might also be classified by equal frequency, such that each of the map classes contains and equal number of observations (e.g. 4 map classes would have N/4 observations in each class). One might also use custom color schemes based on the analysts preferences.
Similarly, point objects might use map symbols (circles, triangles, squares) to denote different types of objects, or the values associated with those objects. The ability to customize the display of maps is in almost all GIS software.
#5 Connectivity
Do you need a desktop GIS software or one that can run in a distributed environment such as the cloud? Will you publish your maps and results locally to the desktop or on the web?
Users must know the type of operating system and hardware that’s required to run the GIS. More complex GIS often require significant memory and computing power, while desktop GIS have a smaller computational footprint. Do you expect to use data you already have on hand? If so, be sure the GIS you are considering can load it.
#6 Functionality
Almost all GIS can generate maps and the ability to work across map layers, using Boolean logic, is also common to most all GIS. Referring back to the forestry example in section 1, the analysis might wish to find conifer stands within 1 mile of forestry roads.
Here a map operation called line buffering would create a map layer recording a buffer of 1 mile to forestry roads. These look like wide lines around the forestry road, something like this.
Next, the analyst might create a classified map showing the presence or absence of conifer stands. The final map product is the intersection of the classified map and the distance to the road map, equivalent to “show me the conifer stands that are within 1 mile of forestry roads”.
Spatial and space-time analysis comprises a large set of statistical analyses and modeling techniques. These include cluster analysis, spatial regression analysis, geostatistics, autocorrelation analysis and multivariate space-time statistical analysis and modeling. Consider BioMedware’s Vesta, for example, which makes available advanced functionality as a desktop software.
#7 User support
A final consideration when evaluating GIS software is the level of user support available.
Of course, the best support is well-designed, easy-to-use intuitive software, along with resources available in the software’s help facility and online on the provider’s website. Especially for software with advanced analysis abilities, it’s comforting to have the opportunity to reach out to experts on the provider’s website. At BioMedware, we also provide online documentation, blogs, and resident experts who can answer your questions.