Tree Testing

Tree Testing

THE METHOD

Poor findability is a major reason for a poor user experience. A tree test is a method that quantifies the findability of an interface (usually a website or software product) by using the labels and structure of the navigation.

Participants are asked to find items or functions in a navigation structure devoid of any design elements or search features.

By removing design elements and the search functionality, we can more easily isolate problems in your taxonomy. Tree testing is often done in iterations or in addition to card sorting and is to a task-based usability test.

MeasuringU provides full support for tree testing, including planning, recruitment, and analysis.

PLANNING

  • Refining research questions, hypotheses, and metrics. We work with the product teams to identify areas that need measurement and be sure the metrics and participants answer research questions.
  • Defining the tasks, writing the scenarios, and recommending pre- and post-study questions. Tree-testing task-scenarios are typically shorter and more to the point than usability task scenarios.
  • Hosting the study in an unmoderated environment using our custom testing platform.
  • Recommending the right sample size. There isn’t a one-size-fits all number; instead the right number is based on the level of precision needed. Most tree tests have between 50-150 participants, which provides a margin of error around 7-9%.  In comparative tree tests (e.g. to alternative trees), the sample size needed is a function of how large a difference exists and is usually at least twice the size of a standalone study (depending on the number of alternatives). A within-subjects study allows for smaller sample sizes than between-subjects studies.

RECRUITMENT

MeasuringU can manage and recruit qualified participants. We assist in developing screeners, scheduling participants, and managing participant honorariums and communication.

ANALYSIS

Tree tests are metrics heavy and focus on participants’ ability to find the information or features. The most common output include

  • Findability rates: The percentage of participants that found the items.
  • Time to find: The median time to find items within the tree.
  • Task difficulty: We use the same post-task Single Ease Question (SEQ) as we do in task-based usability studies.
  • First instincts: Where users click first to find the item. The first click is highly indicative of task success.

In addition to the core findability metrics described above, we also include secondary measures such as where participants backtrack, pogo-sticking (in and out of a category), and provide recommendations on where to improve.

typical engagement price:

$13,000 - $18,000

typical duration:

2-4 weeks