I'm a tester.

Currently when I see something that I don't like I suggest amending it and specify how. However I don't often see specific problems in application's usability and when I do I don't always suggest the most appropriate improvements.

It is often suggested that we incorporate a usability testing phase with end users during specific sessions. But can I do it myself? How can I determine that it's not usable?

6 Answers 6


You should not be doing heuristic evaluation(HE) or cognitive walkthrough(CW) instead of usability testing, but in addition to. Jeff Sauro wrote couple of great post about both methods: "6 things you didn't know about Heuristic Evaluations" and "What’s the difference between a Heuristic Evaluation and a Cognitive Walkthrough?".

Basically according to Sauro there are 6 things you generally don't hear about heuristic evaluation:

  1. You need 3-5 evaluators to get results. Different evaluators find different things. Nielsen's research backs this up (check Nielsen(&Molich) references from early 1990s).
  2. You should do heuristic evaluation in addition to usability testing.
  3. "Rolf Molich, one of the co-creators of the method said "Heuristic Evaluations are 99% bad" at UPA 2009 on a panel with Jakob Nielsen and Chauncey Wilson on Heuristic Evaluations. His reaction was in large part because HE is being used instead of user-testing and only loosely based on any heuristics."
  4. Heuristic evaluation is most effective when evaluators are usability experts and domain experts. (Nielsen, 1992).
  5. There are several sets of heuristics available, not just Nielsen's heuristics.
  6. There is controversy on how effective heuristic evaluation is (Gray & Salzman, 1998).

The second article is about comparing heuristic evaluation with cognitive walkthrough. Both are inspection methods. Biggest difference is that while HE is about heuristics, CW is about tasks user performs.

The main point is that both of these inspection methods are great when done properly and when usability testing is not possible for some reason. Limited money is generally not a great reason to use these methods instead of usability testing as doing HE or CW well is not that cheap.

The things both methods have in common are:

  1. Best evaluators are experts in both usability and domain in question.
  2. Both uncover a lot of usability problems.
  3. Neither can replace usability testing, but can offer valuable feedback especially in situation where usability testing is unfeasible.
  4. Both require the expert to take the user's point of view.
  5. It's best to have multiple evaluators.
  6. Inspection methods can generally cover larger portions of the UI than usability testing.

Sauro also recommends combining both, in essence doing cognitive walkthrough while looking at the UI with the lens of chosen heuristics.

  • 2
    +1 for doing both. Could you summarise what's behind those links (to guard against linkrot)?
    – Rahul
    Commented Jan 16, 2012 at 19:37

Heuristic Evaluation is a good starting place if you're just looking for things yourself. Nielsen's heuristics give you a little bit of focus and something concrete to compare against.

  • ah .. we both have same ideas !! plus one for both ..:P Commented Jan 16, 2012 at 0:50
  • Test-driven development can be a plus. Commented Jan 16, 2012 at 10:04
  • 2
    @NaoiseGolden except that then you're developing in order to pass the various tests, rather than developing to get a functioning usable application.
    – JonW
    Commented Jan 16, 2012 at 10:36

Do a heuristic evaluation and a cognitive walkthrough.

A cognitive walkthrough is basically you as an visitor trying to accomplish the stuff the site is intended to help the visitors accomplish. Meanwhile you are trying to observe yourself and taking notes.

The benefit is that you will get a better understanding of how good the site is at solving problems. It's a good complement to the checklist. The disadvantage is that you are probably more experienced and will solve stuff your visitor wouldn't. But if you run into trouble that is a good indicator that the regular visitor will do to.

More info about cognitive walkthrough


You don't state if you are testing applications for internal use or for products designed for the general public.

The reason for using external testers is so that you will have "fresh eyes" on the testing; they will discover things that you might not have thought of. In general, you will bring certain biases and a background to any test and will focus on what you know and can think of; it is virtually impossible to discover an issue during the test that you have not thought of.

Some examples of factors you might have trouble discovering if you are a typical American include:

What does it look like to someone who is color blind?
How does it work for someone who is visually impaired and uses a screen reader?
Are the help messages clear and unambiguous to someone for whom English is not their native language?


Everyone wants to find the problems themselves.. if it was so easy to do, But then you can follow few things to find the overall usability problems of the applications. This one is one of the best,

Heuristic Evaluation can be practiced by an expert but taken some time, anyone in the team can do it. This gives a good cost-effective benefit.


I suggest going through The ten Heuristics for User Interface Design by Jakob Nielsen.

  • Hi Mohamed, welcome to UX! What do you find recommendable about the ten heuristics for UI design?
    – Rahul
    Commented Jan 18, 2012 at 1:13
  • Thanks, it can be different from a UI to another, in the case of the "Help and Documentation" heuristic: sometimes it is better to make the UI so intuitive that it won't need any documentation, but in this case the designer will have to do some User studies and tests. In general, following the heuristics will prevent common usability problems, and can be performed by the designer him/herself. Commented Jan 18, 2012 at 4:50

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