Presenting results of user testing: Polar Plots

by Randy Tsang

A friend of mine recently put me onto an article entitled “Usability in space science instrumentation” written by Alec McCalden that was recently published in Astronomy & Geophysics journal (his full paper can be read here, see page 189 for the section on displaying results). In it, McCalden applies a lot of what we know about web usability, such as personas and iterative testing to development programmes for space instruments. In this paper, McCalden presents the findings of his usability tests in “polar plots” also known as “spider plots,” examples of which can be found below;

Hubble VTT (2001 - 2006) Interface Results

Hubble VTT (2001 - 2006) Interface Results, Source: A&G, Dec 09, Vol 50, Issue 6

Gemini Position Editor Science Tool (2001 - 2006) Interface Results

Gemini Position Editor Science Tool (2001 - 2006) Interface Results, Source: A&G, Dec 09, Vol 50, Issue 6

To me, these plots seem like an extremely useful tool for producing quick visual assessments of usability tests with a lot of complex parameters and allows for a relatively easy comparison between 2 or more sets of results. The list of testing parameters such as “appropriate use of colour” and “avoid clutter” are displayed around the edges of the graph with the corresponding value of 0 – 5 being plotted within the circle. This results in the production of a relatively arbitrary shape, although as long as the parameters are identical between tests, a comparison can be made. McCalden himself suggests further possible improvements such as grouping parameters together. In the case of web design, parameters could include “aesthetics,” “structure” or “ease of use.” Perhaps some colour co-ordination could help make the assessments quicker.