The other day, I was presented with a problem of visualizing a small 3-D Excel spreadsheet in a way that allowed the viewer to:
- Compare columns for balance.
- Compare the third dimension alternates (professors vs. grad students).
- Compare the rows for balance.
- Compare the overall sums.
What I came up with was this:
Along the ring are the names of the columns of data in the spreadsheet. On each spoke are the rows in the two layers of the spreadsheet visualized as bar charts. Stretching counterclockwise are the bars for senior faculty. Stretching clockwise are the bars for graduate research assistants. In the center, visualized as bubbles of varying radii are the totals from both bar charts along the spoke. Note the light, thin rings connecting each bar. These are designed to draw a viewer’s eye around the chart, connecting bar to bar visually to inform the viewer that comparison is relevant.
This technique is appropriate for smaller charts. I have a feeling that too many columns would get to be too visually busy, although I suspect the chart’s behaviour as rows increase may well be more robust, especially if the bar chart was changed to an area chart.