process improvment

Usability testing vs usability inspections

trojan_control_roomIn the days of Test Driven Development – unit tests, test automation, gui testing, etc. we can unconsciously quit thinking about usability part of application. There will be no errors but helpdesk will stuck with user complains. Usability should be a mainstream in quality assurance team. Testers managers must be thinking globally even if the team tests smallest bugs and changes.

Usability testing
Technique used to check a product on real users. This is black-box method and give us a chance to see user reaction. Often users seat in quiet room, we are standing behind one-way mirror and watching how interaction between user and application go. Before that kind of software meeting, users passes short training or reads some documentation. It is worth to conduct the test without prepared scenario to see free emotions. In the second step we can generate check list with real business cases.

Areas in which we can gain response:

  • Emotional response – How does the person feel about the tasks completed? Is the person confident, stressed? Would the user recommend this system to a friend?
  • Performance – How much time, and how many steps, are required for people to complete basic tasks? (For example, find something to buy, create a new account, and order the item.)
  • Accuracy — How many mistakes did people make?
  • Recall — How much does the person remember afterwards or after periods of non-use?

Great ! but these kind of usability tests are not cheap and often availble at the end of project. Is there any alternative ? How to take care of quality all the time ? This is time to say “Usability inspections !”, which can be performed in paraller to current test process.

Usability inspection
The generic name for a set of methods that are all based on testers group specilized in user interfaces. Typically, usability inspection is aimed at finding usability problems in the design, though some methods also address issues like the severity of the usability problems and the overall usability of an entire system. Many inspection methods lend themselves to the inspection of user interface specifications that have not necessarily been implemented yet, meaning that inspection can be performed early in the usability engineering lifecycle.

  • Heuristic evaluation is the most informal method and involves having usability specialists judge whether each dialogue element follows established usability principles (the “heuristics”).
  • Heuristic estimation is a variant in which the inspectors are asked to estimate the relative usability of two (or more) designs in quantitative terms (typically expected user performance).
  • Cognitive walkthrough uses a more explicitly detailed procedure to simulate a user’s problem-solving process at each step through the dialogue, checking if the simulated user’s goals and memory content can be assumed to lead to the next correct action.
  • Pluralistic walkthrough uses group meetings where users, developers, and human factors people step through a scenario, discussing each dialogue element.
  • Feature inspection lists sequences of features used to accomplish typical tasks, checks for long sequences, cumbersome steps, steps that would not be natural for users to try, and steps that require extensive knowledge/experience in order to assess a proposed feature set.
  • Consistency inspection has designers who represent multiple other projects inspect an interface to see whether it does things in the same way as their own designs.
  • Standards inspection has an expert on an interface standard inspect the interface for compliance.
  • Formal usability inspection combines individual and group inspections in a six-step procedure with strictly defined roles to with elements of both heuristic evaluation and a simplified form of cognitive walkthroughs (source :

All these usability inspection methods often boil down to heaving an expert, who can say “This is good or not” and have adequate reputation in to set a high priority. That judge can also intuit some problems at the early stage of project or even in the idea.

Include in test process ?
Yes, usability inspections should be injected in test process. I can imagine that it will be another level of new functionality acceptance. New functionality which affects user interface and business processes realized by application.

Usability certification and trainings  ?:

Regarding to usability inspections, is good to have an usability expert, some kind of oracle. If You have funds, do an usability tests it helps and sometimes it’s worth to check our expert man. Only human has an intuition which it the key of usability inspections so please do not try to automate 🙂


3 comments for “Usability testing vs usability inspections”

  1. thanks to the author for an interesting article
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    Posted by Cloffboom | March 7, 2009, 3:30 pm
  2. […] is free from errors but above all, ensure us that the usability is also at high level. Use usability testing and usability inspections treat usability as a target. Try to eliminate redundant application paths, do it at early stages of […]

    Posted by 8 Ways to be a Good Software Tester | Test And Try | April 16, 2009, 2:54 pm
  3. […] cycle on my blog, it will be a series of stories about the problems encountered during the “Usability Inspections“. Time to time unexpected and surprising user interfaces solutions. Examples are taken from […]

    Posted by Usability Inspection Surprise #1 | Test And Try | April 17, 2009, 12:51 pm

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