Over the last decade there has been an explosion in data available but most people and organisations have a problem presenting the data. "When dashboards work, they provide a powerful means to tame the beast of data overload. Despite their popularity, however, most dashboards live up to only a fraction of their potential."
Often people obscure the numbers by the way it is presented. Edward Tufte a pioneer in the field of visual communication of information coined the term "chartjunk" to refer to useless, non-informative, or information-obscuring elements of quantitative information displays.
When a dashboard is properly designed, it can provide a powerful way to monitor what is going on at a glance. Two characteristics of a dashboard are largely responsible for this ability:
a) their visual nature and
b) the way they integrate everything you must keep track of, however disparate, onto a single screen
• Do not use pie charts - a bar chart presents the information in a more precise format - see his blog post "Save the Pies for desert".
• Try to avoid visual lies when using a bar chart - start the values at 0.
• 3D graphs are usually not a good choice for business communication. Adding a 3rd dimension adds no extra meaning (and often obfuscates some of the data).
• When showing changes in time - a line graph is often the best choice
• It is OK to use tables of data when you need your audience needs to look up a value or to think.
• Using Excel 2007 data bars are a good visual queue but do not include text over the bars (put it on the side)
The diagram below called a bullet graph was designed by Stephen Few to present a compact, data-rich, and efficient alternative to gauges on a dashboard. Below is an example of a bullet graph with labelled parts.
When creating a dashboard the design should always consider providing quantitative scales so that the qualitative judgments of the data.
The use of colour on dashboards
Did you know that 10% of men and 1% of women are colour blind, and most of them cannot distinguish green from red. On many dashboards you see the traffic lights (green, amber, red) to represent how a particular metric is performing. To someone that is colour blind this looks like (brown, amber, brown). Additionally, colour coding is often overused; this undermines the ability to function effectively. When a designer over uses colour in a dashboard, they do so with the best of intentions. "Colour coding everything, they will make the display easier to comprehend as a whole". Unfortunately, when everything stands out, nothing does.
A common design flaw often seen is a bar chart with 10 to 20 items all with different colours. Using excel has made it very easy to select a set of data and create a graph. Often the series takes up more space than the actual graph.
Edward Tufte also coined the term "Sparkline" for the line chart that displays trends (i.e. no axes or values). This can be a very powerful tool for displaying a metrics behaviour or trend over time.
Stephen Few concluded his seminar with the slide ...
“Eloquence through Simplicity"
Stephen has written a number of white papers and a book on the design of dashboards titled – Information Dashboard Design.
Aleron utilises many of the ideas and recommendations made by Stephen Few, Edward Tufte and other visual design specialists.
For more information contact Jason McIntyre – firstname.lastname@example.org.