UXtweak’s Tree Testing is a navigation exercise, used for testing the information architecture of websites. In each task that respondents receive, they look for a place in the tree where they would expect to find the specified piece of content. Tasks need to have at least one correct answer – or more if what the user is looking for can be found in multiple locations.
Trees are composed of two types of nodes. Group nodes form the tree’s branches, being parents to one or more child nodes found inside them. Content nodes are found at the ends of each branch, so they’re also sometimes referred to as “leaves” of the tree. Only these content nodes can be selected by respondents as correct answers to tasks, while their parents can’t.
There is – naturally – a reason for this. Marking group nodes as answers isn’t in the best interest of the test. We want to find out what path the respondents would take if they were looking for something. We wouldn’t learn anything about movement into deeper layers of the tree if the respondents could just say, “I would find it somewhere in here” and not actually have to find the exact location. The more specific content nodes are where we want the search conducted, not at the group node level.
One reason testers may choose to mark a parent node as the answer is to express the idea that all of its children can be considered correct answers. However, often not all children offer the right solution to the task. Therefore, marking just the parent instead of the exact child would be careless. The only value gained would be saving a little bit of the respondent’s time, but at the cost of you getting information that is incomplete. Even if the respondent is doing it for free, they’ve already taken time out of their day to help you, so they might as well do it properly.
Here are some tips for what to do in situations when you might think that marking the parent as a correct answer might be a good idea:
- When every child of this parent represents a correct option
- When the page itself contains the answer, but it also has some children
When every child of this parent represents a correct option
If for the purposes of your testing, all children of the parent can be considered as correct answers, the solution is simple. Remove the children from the parent node and, as such, turn the group node itself into a content node. This way, the search for the right answer ends here and doesn’t need to go any further.
For example, let’s imagine that you run a tech company, and you want your users to be able to reach your technical support. If that is the goal of your task, you can let the respondents select a content node called Support as the answer, and you don’t need to split it any further into children like “Support email,”, “Support hotline,” and “Support chat” unless this distinction is important to you.
As an alternative, you could give more specific tasks, e.g., “Find where you’d get help fixing a problem with our product on the phone.”
When the page itself contains the answer, but it also has some children
This is a common issue with index pages that have some content of their own, but also link to more specialized sub-pages. Let’s say you have a page about the Olympic Games, which also contains links to pages about the individual Olympic sports (archery, athletics, badminton, etc.). Because the page about the Olympic Games is represented by a group node, it cannot be selected as an answer.
Again, the solution here is simple. Extract the content of the page and then have it represented as a separate child node (e.g., in our Olympic Games example, add Summary as a child of the Olympic Games). As I’ve also written in the blog about how to make good trees for TreeTest, the tree has to represent the content of your website; it doesn’t need to be an exact copy of your menu or an iteration of the way that the pages are structured.