I have yet to see an example in the real world where this type of graph is ever better than another form of graph or chart. However, this article does provide some interesting points about when to use them (or more accurately, when not to use them):

http://www.information-management.com/issues/20050501/1026069-1.html

One potentially useful situation it does mention is showing website traffic per hour. The reasoning the author gives is that people think of clocks when they think of time; and since clocks are circular (well, classically at least), the circular graph can make sense to the user in this regard as well. I personally still prefer a bar graph for that type of report, but I can see the validity of the point being made.

We used radar graphs to compare user profiles along several dimensions. By overlaying the profile radar graphs it was easy to see overlaps and determine segments by dimensions. I liked that they show several dimensions at once and thus an holistic picture - which is appealing to visual thinkers like me. But more analytical persons had a hard time with them, because they tend to see each dimension individually and were frustrated because they could not easily compare the numbers.

PS: I vaguely remember that radar graphs came from Japan, so you are likely to find many more examples there. It also explains why radar graphs are not (yet) as popular here in the Western world.

Hi Philip

I've not seen radar graphs used that frequently. However, I have used them in the past to visually demonstrate a website effectiveness against common user experience benchmarks. The radar graph enabled me to provide a high impact way of comparing a client's site against their competitors.

Example:

Evaluation Criteria

A website is evaluated and ranked out of 10 against the following quality criteria

• Useful – Is the product/services useful to the customer?
• Usable – Is the product/services usable?
• Understandable – Does the associated content and editorial make sense?
• Desirable – Do customers want/identify with the product/service?
• Findable – Is the product/services information structure efficient?
• Accessible – Is the product usable for people with disabilities?
• Credible – Is the product/services trustworthy?
• Valuable – Is the product/service valuable to the business?

Their score is then plotted on a radar graph which visually shows the areas that rank well and the areas which need more work. At the time I worked on the principle that a score of 5 or under warranted focused development.

HTH

Matt

I've never used them in an electronic form.

I've have used them on paper in things like team retrospectives when we want to discuss how well we think we're doing on a number of dimensions. In those instances we tend to look at the overall "shape" of the graph and compare it to previous months where we can see whether we have improved in the areas we wanted to.

I've never really thought about why I use radar charts in those situations. It's just a technique I was shown once and it seemed to work well.

I'm guessing that since these are graphed so "bad" values are close to the centre and "good" values are near the rim you can easily see whether you're getting a reasonable balance by whether you're getting a nice round shape. People seem to get a quite visceral feel for "bad" shapes which are small/spikey and "good" shapes that are large and round.