Heuristic analysis is an extremely useful usability inspection method. It is a technique used in the UX Design process to test usability. Typically, in heuristic analysis, 3–5 usability experts will review the product and compare it against pre-defined principles — the heuristics. From this, they can highlight any usability issues before the product goes into user testing. This is great, as it cuts down on obvious usability errors and improves the testing process.
The most commonly used heuristics include:
- Jacob Nielsen’s Heuristics for User Interface Design
- Ben Shneiderman’s Eight Golden Rules of Interface Design
- Jill Gerhardt-Powals’ 10 Cognitive Engineering Principles
- Christian Bastien and Dominique Scapin 18 Ergonomic criteria for the evaluation of human-computer interfaces
- Bruce Tognazzini’s First principles of interaction design
- William Lidwell, Kritina Holden, and Jill Butler’s Universal principles of design
- Alan Cooper’s About face 2.0: The essentials of interaction design.
One of the most famous heuristics came from Jacob Nielsen and Rolf Molich in 1990. This is still the most used heuristic in usability inspection.
Another good example for usability heuristics is Susan Weinschenk's and Dean Barker's (Weinschenk and Barker 2000) research on usability heuristics. Here's a list produced based upon that:
- User Control: The interface will allow the user to perceive that they are in control and will allow appropriate control.
- Human Limitations: The interface will not overload the user’s cognitive, visual, auditory, tactile, or motor limits.
- Modal Integrity: The interface will fit individual tasks within whatever modality is being used: auditory, visual, or motor/kinesthetic.
- Accommodation: The interface will fit the way each user group works and thinks.
- Linguistic Clarity: The interface will communicate as efficiently as possible.
- Aesthetic Integrity: The interface will have an attractive and appropriate design.
- Simplicity: The interface will present elements simply.
- Predictability: The interface will behave in a manner such that users can accurately predict what will happen next.
- Interpretation: The interface will make reasonable guesses about what the user is trying to do.
- Accuracy: The interface will be free from errors
- Technical Clarity: The interface will have the highest possible fidelity.
- Flexibility: The interface will allow the user to adjust the design for custom use.
- Fulfillment: The interface will provide a satisfying user experience.
- Cultural Propriety: The interface will match the user’s social customs and expectations.
- Suitable Tempo: The interface will operate at a tempo suitable to the user.
- Consistency: The interface will be consistent.
- User Support: The interface will provide additional assistance as needed or requested.
- Precision: The interface will allow the users to perform a task exactly.
- Forgiveness: The interface will make actions recoverable.
- Responsiveness: The interface will inform users about the results of their actions and the interface’s status.
- It can be quick and cost effective.
- It can be used early in the design process, even in wireframes.
- It can give a comprehensive usability status of a product.
- With the right heuristic measurement, the best corrections can be made.
- It can be used together with other usability testing methods.
- Afterwards, usability testing can further examine potential issues.
- Collect the product you want to test;
- A minimum of 3 experts are recommended;
- Define the heuristics you want to use.
Before you start:
Without any groundwork or research, heuristic analysis will not be highly accurate. So,
- You need to know and understand the business and user needs of the product/system, and how they are aligned with each other;
- You should be up to date with existing research results such as stakeholder interviews, user research, questionnaires, personas, user journey maps and scenarios;
- You need to understand user motivation, what tasks they want to accomplish, and what their main goals are.
- Define and choose the heuristics you want to use. If you don’t know, we would recommend Neilsen’s or Gerhardt-Powals'.
- Select your evaluators. They should have experience in usability / UX, and you should give them all the same training on principles and processes to ensure they’re interpreting the heuristics correctly.
- Set up a consistent evaluation system (critical issue, normal issue, minor issue, good practice), or traffic light scheme (red, orange, yellow, green), and make sure the experts understand them.
- Highlight where the problem is (the page/screen, location on the page) and how big a problem it is (rating scale)
- Compare and analyse results from the multiple experts. The benefit of having multiple experts is that although they will likely find many of the same errors, they each will also find some issues the others have missed. We would not recommend using more than 3-5 experts.
The cognitive walkthrough is a task focused heuristic evaluation method where one or more usability experts work through a series of tasks and ask a set of questions from the user's perspective. This method derives from the notion that users prefer to learn a system by using it to accomplish tasks, rather than studying a manual.
Blackmon, Polson, in their paper “Cognitive walkthrough for the Web” offer four questions to be used by an evaluator during a cognitive walkthrough:
- Will the user try and achieve the right outcome?
- Will the user notice that the correct action is available to them?
- Will the user associate the correct action with the outcome they expect to achieve?
- If the correct action is performed; will the user see that progress is being made towards their intended outcome?
You ask these questions before, during and after each step in the ideal path. If you find an issue, you make a note and then move on to the next step of the task.
Both Heuristic analysis and cognitive walkthrough are good to go as soon as the first design iteration is ready, starting with the wireframes. Once their recommendations have been implemented, you can start user testing:
Now that you know the differences between these usability inspection methods, you can start implementing them in your design process. Use them early and often in your design process and reap the benefits of a better user experience for your users.