Chart Experiment: Harvey Balls Sparkline

 

Harvey balls are round ideograms used for the visual communication of qualitative information. They are commonly used in comparison tables to indicate the degree to which a particular item meets a specific criterion.

For example, in a comparison of products, information such as price or weight can be conveyed numerically, and binary data such as the existence or lack of a feature can be shared with a check mark; however, information such as "quality" or "safety" or "taste" is often difficult to summarize in a manner allowing easy comparison – thus, Harvey balls are used.

In addition to their use in qualitative comparison, Harvey balls are also commonly used in project management for project tracking; in lean manufacturing for value-stream mapping and continuous improvement tracking; and in business process modelling software for visualisation.

Such a simple visual that is similar to a pie chart. The Harvey balls are seemingly being missed out in mainstream visualisation. I have seldom seen them being used despite them being intuitively easy to read. Admittedly, they are not intended to be read in the way below:

To a similar effect, I have tried to use it in one of my visualisations as a representation of levels here in my submission for Data Arcade Tournament 2022 (DAT 2022):

Taking it further, the above format can be placed in a timeline as shown below:

Easy enough to read. Simple enough to understand. The Harvey balls show the progress of each item clearly along the line. Borrowing Edward Tufte's idea of sparkline, we can remove the excess information and present it as shown below:

Colours can also be further added to signify more dimension.

Nevertheless, the issue of an area being harder to read than a shaded length (i.e. bar chart), similar to the pie chart stays. Also, the progress percentages are mainly from the 5 stages at each quarter of a pie chart.

All in all, this has been an obvious yet fun experiment.