If I had a penny for every time I heard the phrase ‘Rules are meant to be broken,’ I’d be rich. However, this cliché has no place in BI dashboard design. Having the right dashboard charts and graphs are essential to making your dashboard a useful resource. Your users may not be able to articulate it – since they may not know better – but your dashboard may be the victim of what we call a “chart foul.” Chart fouls can be detrimental to the usefulness of your dashboard because they indicate that data isn’t being presented the right way, or they mean that your chart type or data labels are confusing your users.
We’ve been building BI dashboards for the last 18 years for large and small companies. You can probably imagine the number of chart fouls we’ve come across. Today we’ve pooled our knowledge and present to you some pointers on major chart fouls to avoid:
1. Choosing the wrong chart type.
Have you ever seen a bar chart with more than 15 data sets? That’s a considerable amount of information to display horizontally, so chances are that the graph appeared very cluttered and was difficult to read. You’re better off displaying such information as a simple line graph. How about a radar graph showing the qualitative scores of potential hires? It’s just as confusing as it sounds (see below), and is probably not a good idea either. So in order to show ranking among candidates, a good old-fashioned table of numbers will do. Choosing the right graph or chart for your data is an art. You should select a graph that is easy to understand and is an appropriate representation of your data. In a previous post on Dashboard Charts & Graphs, we reviewed how to choose the best chart type for your BI dashboard.