Tree testing
{{About|a technique used to evaluate the usability of a website|the personality test also known as tree test|Baum test}}
{{more citations needed|date=August 2018}}
Tree testing is a usability technique for evaluating the findability of topics in a website.{{Cite book |last=Hanington |first=Bruce |title=Universal Methods of Design, Expanded and Revised |last2=Martin |first2=Bella |publisher=Rockport Publishers |year=2019 |isbn=9781631597497 |location=Beverly, MA |pages=232 |language=en}} It is also known as reverse card sorting or card-based classification.{{cite web
|title=Card-Based Classification Evaluation
|url=http://boxesandarrows.com/card-based-classification-evaluation/
|author=Donna Spencer
|date=April 2003
}}
A large website is typically organized into a hierarchy (a "tree") of topics and subtopics.{{Cite book |last=Chesnut |first=Donald |title=UX for dummies |last2=Nichols |first2=Kevin |publisher=Wiley |year=2014 |isbn=9781118852781 |location=West Sussex, England |pages=141 |language=English}}{{Cite book |last=Palade |first=Vasile |title=Knowledge-based Intelligent Information and Engineering Systems. |publisher=Springer Nature |year=2003 |isbn=978-3-540-23318-3 |pages=250 |language=English}} Tree testing provides a way to measure how well users can find items in this hierarchy.{{Cite book |last=Elleithy |first=Khaled |title=Advances in Systems, Computing Sciences and Software Engineering : Proceedings of SCSS 2005 |last2=Sobh |first2=Tarek |publisher=Springer |year=2006 |isbn=9781402052620 |location=Dordrecht |pages=232 |language=en}}{{Cite book |last=Paraguacu |first=Fabio |title=Intelligent tutoring systems : 6th International Conference, ITS 2002, Biarritz, France and San Sebastián, Spain, June 2-7, 2002 : proceedings |last2=Gouarderes |first2=Guy |last3=Cerri |first3=Stefano A. |publisher=Springer |year=2002 |isbn=978-3-540-43750-5 |location=Berlin; London |pages=743 |language=English}}
Unlike traditional usability testing, tree testing is not done on the website itself; instead, a simplified text version of the site structure is used. This ensures that the structure is evaluated in isolation, nullifying the effects of navigational aids, visual design, and other factors.{{Cite book |last=DESAI |first=SANDEEP |title=Software Testing |last2=SRIVASTAVA |first2=ABHISHEK |publisher=Phi Learning |year=2016 |isbn=9788120352261 |pages=310 |language=en}}
Basic method
- The participant is given a "find it" task (e.g., "Look for men's belts under $25").{{Cite book |last=Sharon |first=Tomer |title=Validating product ideas: through lean user research |last2=Gadbaw |first2=Benjamin |publisher=Rosenfeld Media |year=2016 |isbn=978-1-4571-9077-3 |location=Brooklyn, NY |pages=275 |language=English}}
- They are shown a text list of the top-level topics of the website.
- They choose a heading, and are then shown a list of subtopics.
- They continue choosing (moving down through the tree, backtracking if necessary) until they find a topic that satisfies the task (or until they give up).
- They do several tasks in this manner, starting each task back at the top of the tree.
- Once several participants have completed the test, the results are analyzed.
Analyzing the results
The analysis typically tries to answer these questions:
- Could users successfully find particular items in the tree?
- Could they find those items directly, without having to backtrack?
- If they couldn't find items, where did they go astray?
- Could they choose between topics quickly, without having to think too much?
- Overall, which parts of the tree worked well, and which fell down?
Tools
Tree testing was originally done on paper (typically using index cards), but can now also be conducted using specialized software.{{Cite book |last=Soares |first=Marcelo M. |title=Design, User Experience, and Usability: UX Research, Design, and Assessment |last2=Rosenzweig |first2=Elizabeth |last3=Marcus |first3=Aaron |publisher=Springer International Publishing AG |year=2022 |isbn=9783031058967 |location=Ch |pages=84 |language=en}}