The traditional approach to publishing maps on the Internet "by GIS experts, for GIS experts" is outdated, ineffective and unusable as Web mapping becomes more and more mainstream.Applications need to be designed for ease of use, and cater for users whose mapping experience is limited to reading a street directory.This rapidly increasing audience can no longer be expected to be GIS savvy.They won't wade through complex interfaces or wait more than 30 seconds for a map to appear.
This article presents guidelines and some of the dos and don'ts of Web mapping design.Among other subjects, it will look into aspects of Web design such as user profiling, task definition and usability testing. It will examine some recent best practice case studies to illustrate these points.
Three Categories of Mapping Apps
These days, we can distinguish three main categories of mapping applications, each with a different audience, and having different functions and requirements.There is a clear link between audience, tasks, functional requirements and development team skills in each category.
(1) Desktop GIS (or if you prefer workstation GIS), is typically used by your local GIS guru using the ACME GIS package.It is jam-packed with advanced functions and offers flexibility.Its usability is targeted at expert users.It is, of course, expensive.
With the advent of ubiquitous networking, many organizations are now turning to (2) online GIS to deliver basic GIS functionality to a wider audience.The planner, the ecologist and the firefighter use it.These people are business users and knowledgeable stakeholders, rather than GIS experts.They may have some training, but they are happy to trade some functionality and flexibility for ease of use.
(3) Web mapping is what gets typically delivered over the Internet or on a mobile device.It is characterized by a defined purpose or scope, many users and ease of use, and is generally aimed at the public at large.Even if it is aimed at a specific interest group, we can assume they are novices with respect to computerized mapping.
Web Mapping and Usability
The technology that makes Web mapping possible has been around for more than a decade.However, mainstream applications have only been emerging in recent years.With a few notable exceptions (such as MapQuest and WhereIs), most Web mapping applications have been designed by GIS experts.The result has often been an attempt to cram as much GIS functionality and flexibility as possible into the application.This is fine if the target audience is our peer group.However, this is rarely the case, which is why many Web mapping applications are currently gathering dust, and are wilting away at 'proof of concept' stage.
Encouragingly, this pattern is changing.Web mapping is becoming more integrated with mainstream Internet applications.Expectations with respect to quality and usability are maturing.Web mapping projects more and more include extensive user profiling, requirement analysis, graphics design and usability testing.
Usability is a term used to define how easy it is for the target audience to use a product or service.It also describes a process of improving the ease of use of a product during its design and refinement.Closely related to usability is utility, which relates to functionality (e.g., does it do what I need?).
Addressing these two attributes is critical in improving the acceptance of a product or service.Jacob Nielsen (also known as The King of Usability) suggests that usability has five quality components:
- Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
- Efficiency: Once users have learned the design, how quickly can they perform tasks?
- Memorability: When users return to the design after a period of not using it, how easily can they re-establish proficiency?
- Errors: How many errors do users make, how severe are these errors, and how easily can they recover from errors?
- Satisfaction: How pleasant is it to use the design?
- Identify the target audience.Who are they, what experience do they have using Web mapping tools, paper maps, the Internet etc.?
- Identify their requirements.What do they want to accomplish, what are their priorities, where will they use the tool? This can be done in a variety of ways including observing the user undertake tasks in their own environment, interviews, questionnaires, focus groups, etc.
- Summarize requirements, opportunities and constraints.Determine what types of map and functionality will meet their requirements.Do they need static or live interactive maps? What information needs to be on the map? What is the appropriate functionality: zoom, pan, printability, save and/or data analysis? This summary will act as a reference for the design and can be modified as the design is refined.
- Develop a prototype.This could be drawings on paper of different screens or a basic online version of the tool.It does not have to be a fully functional version at this stage as the whole point of this process is to inform the design before too much investment, or a commitment to a certain course of action, has been made.
- Test the prototype with a small number of representative users using representative tasks.Write some tasks, get representative users to try to do them using the prototype, and observe the issues they encounter.Remember not to interfere or you will bias the results.It can be very powerful for members of the project team to sit in on these sessions to observe and hear first hand the issues and suggestions.Following the testing, analyze the results and develop changes based on how many users the issue will affect and how often.
- Refine the prototype and test again.Repeat this step until the design has achieved an appropriate level of utility and usability.
- Build the tool.
There are many guidelines to consider when designing Web mapping applications.Here are some to consider.
Novice users should be able to view and interpret the map without the possibility of making errors.They should never get confused.
Access to advanced functionality such as adding layers or querying data should be available for experts.However, these functions should not act as a block for novice users.
- Terminology should be clear and unambiguous. Designers should avoid jargon.
- Use professional designers to improve the graphic design of the site.The design should enhance and complement the text and the maps, focusing the user's attention on the content.
- A meaningful legend should be presented as part of the default view of the map so that the map is self explanatory.
- Provide a locator, or context map, that shows where the map being viewed is in relation to a larger geographic area.
- Buttons should have text or icons that have "ALT text" with their name, and describing the purpose or action.They should be large enough for users to accurately identify the text or image and to click with their mouse.
- Help must be provided and there must be a range of appropriate error messages, including the action that is required to enable recovery from an error.
Online mapping has matured.If we as spatial professionals want it to be taken seriously, and see Web mapping being taken up as part of mainstream Web content, consideration of usability aspects will be absolutely essential.That means starting with an analysis of the target audience and their requirements, designing and developing a prototype, and iteratively testing and refining the prototype with the target audience.Web designers and usability professionals will need to become part of the core development team, or else we will continue to find our audiences sitting like a rabbit in the headlights, instead of actually using the site.
Ed.Note: This article first appeared in Position Magazine.