Find WHO? Tree-testing the World Health Organization

3 min read Optimal Workshop

The theme of World Usability Day 2013 is healthcare, so we thought it would be useful (and fun) to test the findability of a few prominent healthcare websites.

In this article, we’ll look at the results of a tree test on the website of the World Health Organization (WHO). While this is not a comprehensive study of the site’s usability, it does give us a quick way to evaluate the WHO site’s organization and labeling.

We set up the WHO site’s structure in Treejack, created 9 tasks that covered common scenarios that the general public might encounter, then used Amazon’s Mechanical Turk to get 80 people to do the tree test.  So, how well did the WHO’s site structure perform?

Overall results

Overall, the WHO site did a respectable job of getting their site visitors to the right place. 68% is at the high end of average for websites in general:

However, there was more than the usual amount of backtracking to get to the correct answer. Almost 40% of the time, participants had to back up and try a different path:

For example, when asked to look for a specific book, some participants tried the Media Centre section (reasonable, considering that books are “media”). However, our treejack analysis showed that they quickly found they were in the wrong section, and backed out (indicated by the blue color-coding for Media Centre below):

Labels – good and bad

Part of this confusion was caused by headings that were not clear and distinguishable from each other. For example, for printed materials, participants had no problem finding the Publications section, but then had a hard time choosing between “reports”, “publications”, “journals”, and “guidelines”.

Contrast this with some good labeling. Participants were asked to look for “How many people died in Mexico in 2008?”. On this task, the Data And Statistics section did its job well, its clear label attracting most of the traffic down the right path:

The importance of cross-linking

Like any large content site, the WHO website offers several different ways to browse – by health topics, by programmes, and so on. While this sounds good in theory, it also confronts users with more choices, which can make items harder to find.

Happily, the WHO site does a reasonably good job of cross-linking between their various sections. For example, the “dangers of arsenic in drinking water” lives in the Programmes section, but participants could easily get there by following clearly labeled links in other sections. The pie tree below shows that most participants went to Health Topics, where it was listed under “Arsenic” and “Drinking water” (but curiously, not under “Water” itself):

Unfortunately, the WHO site missed some cross-linking opportunities in other tasks, such as “Get a contact number for the WHO Office at the United Nations.” While many found the right answer in About WHO, many went instead to the Contact page in the Media Centre section, which has no information about the UN office they were looking for.


In terms of findability, the WHO site’s mixed results are typical of large content sites:

  • Some good labeling based on clear everyday terms is mixed with some downright confusing organizational jargon.
  • Some common tasks benefit hugely from the safety net of judicious cross-linking, while other commonly searched-for items are buried in a single section while participants wander around other likely sections and meet surprising dead ends.

In the second installment of this series, we’ll look at another well-known healthcare site – the Mayo Clinic. Stay tuned!

This website review was developed, analyzed and written by Dave O’Brien (UX professional).