Visualizing Data in Excel Geof Hileman, FSA Kennell & Associates, Inc June 4, 2012

FOR OFFICIAL USE ONLY 2 Do you need a chart? But first … do you really need a chart? Questions to consider: 1) Will the audience need the raw data anyway? 2) Are you trying to communicate something about the relationship between two variables (or one variable over time?) 3) Is the data being represented reference data to be used for another purpose? You may be better off with a clean data table.

3 Do you need a chart? Are you trying to present data for analysis or telling the reader one number? Don’t make your audience work just because you wanted to make a graph! FOR OFFICIAL USE ONLY

4 Do you need a chart? FOR OFFICIAL USE ONLY

5 Do you need a chart? Pictorial superiority effect: - After 72 hours, 10 percent of information presented orally will be recalled percent of information presented pictorially will be recalled. How much of this slide will you remember? FOR OFFICIAL USE ONLY

6 Pictorial Superiority Effect 72-Hour Recall 10% 65% Presented Orally Presented Pictorially

FOR OFFICIAL USE ONLY 7 Better Excel Charts What about “Chart Junk”? Chart Junk (Tufte, 1983): The interior decoration of graphics generates a lot of ink which does not tell the viewer anything new. The general purpose of the decoration varies – to make the graphic appear more scientific, to enliven the display, to give the designer an opportunity to exercise artistic skill. Regardless of its cause, it is all non-data-ink or redundant data-ink, and it is often chartjunk.

FOR OFFICIAL USE ONLY 8 Better Excel Charts What about “Chart Junk”?

FOR OFFICIAL USE ONLY 9 Better Excel Charts Line Graphs Avoid use of a legend whenever possible.

FOR OFFICIAL USE ONLY 10 Better Excel Charts Line Graphs – Secondary Axis A secondary axis can be used to combined two concepts on a single chart, but beware of confusing the reader. Add the data series to the chart. May have to change the axes to make visible. Choose new series; “Format Data Series”; “Series Options”; “Plot on Secondary Axis”

FOR OFFICIAL USE ONLY 11 Better Excel Charts Line Graphs Use trendlines to tell the story.

FOR OFFICIAL USE ONLY 12 Better Excel Charts Line Graphs Additional suggestions: - Logarithmic scale can be useful. - If it’s too busy, try multiple graphs. - Data markers are often unnecessary. - Be careful with color. Please don’t make this graph!

FOR OFFICIAL USE ONLY 13 Better Excel Charts Bar Graphs A bar chart’s purpose should be to illustrate differences in relative magnitude. Critical decision is how to group the bars. Consider the six possible choices in the example to the right.

FOR OFFICIAL USE ONLY 14 Better Excel Charts Columns or Bars?

FOR OFFICIAL USE ONLY 15 Better Excel Charts Bar Graphs Can use overlapping bars to demonstrate relationships. How to … Right click on the “inner” data series and choose “secondary axis”. Adjust the sliders until the desired effect is achieved. Set the axes to be identical. Delete one of the two axes.

FOR OFFICIAL USE ONLY 16 Better Excel Charts Which negative trend is more alarming? Source:

FOR OFFICIAL USE ONLY 17 Better Excel Charts Waterfall Charts

FOR OFFICIAL USE ONLY 18 Better Excel Charts Pie Charts Pie charts are everywhere, but have gotten a bad reputation for being ineffective. Purpose of a pie chart should be to compare a slice to the whole rather than to compare two slices.

19 Better Excel Charts Pie Charts Why are pie charts poorly suited for comparing the contribution of two slices? FOR OFFICIAL USE ONLY

20 Better Excel Charts Pie Charts FOR OFFICIAL USE ONLY

21 Better Excel Charts Pie Charts FOR OFFICIAL USE ONLY

22 Better Excel Charts Pie Charts Tips for effective pie charts: - Make sure you’re using them for the right reason. - Think carefully about data labels, legends. - Don’t go 3-D – it just makes the eyeball’s job even harder. - Let color complement, not distract. Image source:

FOR OFFICIAL USE ONLY 23 Better Excel Charts The Speedometer Speedometer charts, while not straightforward to create, can be powerful tools in displaying a status relative to established benchmarks. Image source:

24 Dashboards Dashboard: A collection of graphs and/or tables summarizing established key performance metrics. DashboardsReports Intended for quick consumption Target audience: upper level management Purpose is to alert decision makers to potential areas of concern, leading to additional analyses Standardized and uniform. Require lots of planning. Measures metrics against predetermined benchmarks Intended to answer multiple possible questions Target audience: analysts Purpose: to provide answers to questions that might come from executive reviews of dashboards More flexible and contextual. More development time than planning. Just the facts FOR OFFICIAL USE ONLY

25 Dashboards FOR OFFICIAL USE ONLY Source: Sample dashboard: Uses color to make the point Uniform view on the page Integrated into a web page Single page

26 Dashboard Concepts with Excel Conditional formatting can turn an ordinary table into a flexible dashboard-type presentation of data. OriginalColor ScalesData BarsIcons FOR OFFICIAL USE ONLY

Dashboard Concepts with Excel 27 FOR OFFICIAL USE ONLY