Dashboard basics
“A dashboard is a visual display of the most important information needed to achieve one or more objectives; consolidated and arranged on a single screen so the information can be monitored at a glance”
-Stephen Few, Information Dashboard Design
Visualization consultant and author Stephen Few’s definition highlights several distinguishing characteristics of effective dashboards. A good dashboard:
- Displays information visually
- Has a clear sense of purpose
- Fits on one screen
A car’s dashboard provides the information a driver needs to operate the vehicle safely. Information that must be acted on quickly needs to stand out, such as the light indicating a near-empty fuel tank. In a business environment a dashboard-style report might provide a regular snapshot of activities and call attention to areas that need attention (e.g. because of an unexpected change).
In Tableau software the term dashboard refers to a display that combines graphs from multiple Tableau sheets along with labels and other visual elements. Some Tableau dashboards are similar in function to the dashboards of vehicles; others are like infographics or interactive reports that tell a story or provide visual access to a dataset.
Whether you’re creating an interactive visual report or a dashboard for continuous monitoring, clarity about purpose and audience will help you decide what to include and how to present it well.
Some guidelines for effective dashboards
I draw on the work of visualization experts Stephen Few and Alberto Cairo to offer a very short list of guidelines for dashboard design (see the Resources page for references.)
Provide sufficient context
“Don’t trust chart authors and publishers who don’t mention the sources of their data or who don’t link directly to them.”
-Alberto Cairo, How Charts Lie, p.l05
If you want viewers to trust your reports be upfront about the data they are based on. This is standard practice an academic environments but is sometimes overlooked when dashboards or visualizations are presented independently. In addition to citing your data source, make sure you provide enough context for a viewer to interpret the dashboard correctly. The right amount of contextual information may depend on your intended purpose and audience.
Nothing unnecessary
The visual field can become cluttered quickly, whether because of unnecessary decorative elements or information that is not relevant to the dashboard’s main purpose. It is helpful to ask whether each element in a dashboard contributes to the intended use. A graph may be attractive or interesting in its own right, but not a good fit for a particular dashboard.
This also applies on a smaller level: avoid labels that provide more precision than you need as they take up space and attention (e.g. don’t show 2.073% in cases where 2.1% is enough).
Appropriate chart types
Some chart types are more suitable than others for conveying certain types of information. The books listed on the Resources page provide in-depth information and examples about the application of various chart types. An effective visualization takes advantage of how the eye and brain processes information, as described in Stephen Few’s article Tapping the Power of Visual Perception. When presenting quantities, for example, it’s easier for people to compare the relative length of bars in a bar graph than the size of slices in pie graph.
Appealing arrangement
“Well-designed charts aren’t just informative but also graceful and, like a good turn of phrase, sometimes even playful and surprising.”
Alberto Cairo, How Charts Lie, p.47
Visual clarity and aesthetic appeal contribute to the effectiveness of a dashboard. This isn’t only about calling attention with something pleasing to the eye: it’s about using layout, colors, and design to help the viewer focus on what matter most.