The benefits of heuristic evaluation
By Laure Gabrielle Chatenet
and Ousama Jaâfour
Heuristic evaluation is a method of inspecting the ergonomics and design of an HMI interface, while referring to a set of standardized ergonomic criteria.
What is the purpose of heuristic evaluation?
Heuristic evaluation helps optimize usability by minimizing design deficiencies. It thus guarantees the effectiveness of the interface of a digital device, such as a website, a mobile application or SaaS software.
Indeed, there are 2 types of evaluation:
- Formative assessment : applied during the design phase. In particular, it can be carried out on a prototype. This type of inspection verifies that the work is heading in the right direction.
- Summative evaluation : it is carried out at the end of the design, on a finalized and functional interface. This type of inspection essentially makes it possible to evaluate all the work, in its entirety, after its completion.
The ergonomic audit represents an iterative process, which is carried out by specialists in HMI ergonomics, who refer to a heuristic grid to conduct their assessments, or precisely to the Capian tool, which brings together a whole range of heuristic criteria.
Especially, the 10 heuristics of Jakob Nielsen and Bastien & Scapin are the best known on an international scale and the ergonomic criteria of Bastien & Scapin are the most used on a French-speaking scale.
Failure to respect these rules means that there is a usability problem. In other words, each problem identified relates to a specific heuristic. This helps the UX Designer to directly identify the source of a problem and save time.
Although heuristic evaluation helps to identify problems with the web or mobile interface, it does not provide solutions to solve them. However, it does shed light on the most deliberate choice to be made to optimize the interface's efficiency.
The influence of heuristic evaluation on user experience
Usability heuristics are essentially based on these principles:
- Simplicity: the design of the GUI interface must be simple and minimalist, in order to optimize and facilitate the user's journey and create empathy. In addition, navigation must be fluid and intuitive to guide the user directly to the information he is looking for.
- Consistency: The UX Design must be consistent across all system interfaces. The symbolism of the icons must be easily assimilated. Images must be of high quality and must adequately illustrate the content. The graphic forms must be in line with the brand's graphic charter.
- The readability: The choice of colors and the hierarchy of the UI components must ensure a better readability of the interface. This guarantees to attract the user and arouse his curiosity to discover the digital device.
- Accessibility: The interface must be flexible and responsive, so that it can adapt to the different screen sizes of the target devices: computer, smartphone, tablet, etc.
- Attractiveness: the aesthetics and ergonomics of the interface must attract the user and encourage him to take action (purchase, registration, etc.).
Good UX is the key to user satisfaction and increased loyalty. According to a recent study conducted by Forrester Research, a perfectly designed user interface can achieve a conversion rate of approximately 200% for a website. On the other hand, a good UX Design can achieve up to 400% conversions.
So, you'd better follow the above principles. The heuristics will help you validate that you've respected those principles.
Heuristic Evaluation of User Interfaces par NN/g
Most common usability problems
Usability flaws reduce the relevance of the user interface and generate a sense of frustration for the user. The most common usability problems are mainly related to content, security, accessibility, ergonomics, and information prioritization.
Problems related to content
Here are the most common failures:
- poorly structured content,
- content that is not up to date and full of errors.
- content that is poor in meaning and useful information,
- texts that are too long and illegible.
- abusive use of technical language ;
- inappropriate or incomprehensible wording.
- The most popular security problems are manifested in the weakness of the system's protection measures against cyber attacks.
- This may be the result of :
- the absence of authentication rules,
- indexing of confidential files, making them visible to the public.
- the absence of an SSL certificate.
Problems related to accessibility
The most glaring problems concern :
- a confusing navigation plan.
- a heavy and annoying page scrolling.
- inconsistency between links and destination pages.
- incompatibility between browsers and platforms. That is to say, the system is neither cross-browser nor cross-platform.
- bulky multimedia elements (video, animation or images) that make the page loading heavy.
- Complex page URLs that are difficult for the user to remember.
Accessibility UX Insights
Ergonomics related problems
The most common ergonomic problems are :
- Colorimetric chaos and contrasts that obstruct vision.
- A design cluttered with superfluous elements.
- A rather large font size and an extravagant choice of fonts, which paralyzes reading.
- Lack of coherence between the interface components: colors, animations, text and fonts.
- Failure to respect ergonomic conventions and web standards.
- The bug of some UI components, such as: a button that is clickable but disabled, a link that does not change its appearance when visited or does not work when clicked.
- Absence of contact forms.
- Absence of the search function.
- Obligation to register before consulting the product/service, etc.
Problems related to the hierarchy of information
The most common problems are :
- random and inappropriate positioning of interface elements.
- Lack of hierarchy in the information architecture.
- Lack of transparency of information.
Qu’est ce que l'architecture de l’information ?
Advantages and conveniences of heuristic evaluation
Heuristic evaluation is an intuitive method, easy and quick to implement.
It allows you to :
- Identify usability issues. In the case of a formative evaluation, the evaluator may disclose these deficiencies earlier in the design process. This is very beneficial for the development cycle and saves more time in the integration of web mock-ups.
- Identify several problems, which helps to raise the awareness of the team involved of the level of criticality and complexity of these concerns.
- Save money, as this method is inexpensive to implement. In addition, it does not require the recruitment of candidates to perform the audit. The assessor can put himself in the end-user's shoes and perform the assessment by himself.
- Detect minor problems, which often go unnoticed during usability testing.
- Assess the impact of interface problems on the overall quality of the user experience.
In order to obtain conclusive results, it is necessary to call upon experts in the field who master these heuristics and who can inspect the interface in an optimal way. Moreover, this is not always obvious for all companies.
In light of this statement, Capian brings its innovative solution, which is manifested in a heuristic evaluation tool. It is an intuitive and easy to use UX evaluation tool. The evaluator can perform his UX audit easily and efficiently thanks to these functionalities:
- Pre-recorded evaluation heuristics, such as Nielsen, Bastien and Scapin criteria, Amélie Boucher…
- Customized heuristics that correspond to the needs of the company and the type of interface to be inspected.
- Easy capture of the area to be audited through the chrome extension. This capture opens a dialog box that allows the evaluator to create his observation report quickly and smoothly.
- Sharing information by centralizing all UX evaluation files in a Cloud space, which is accessible to all team members, anytime and anywhere.
This online collaborative space optimizes communication between team members, who can work, in real time, on the same file or report (which gathers several files). For example, they can import one report into another and exchange comments and files with each other.
Capian not only eliminates the time-consuming discourse of decision making and discussion among evaluators, but also helps them work in a more organized, consistent, and efficient manner.
Thanks to this tool, all team members will have a common and clear vision on :
- The different usability issues of the system. Thus, evaluators can prioritize these problems.
- Interfaces that have a faulty design.
- The potential optimizations to be achieved.
Having a unified vision of the ergonomic assessment project avoids obtaining diverse results that vary from one assessor to another. This leads to more reliable findings.
The heuristic approach has some shortcomings, namely :
- The effectiveness of this method is closely linked to the competence of the evaluator, the more qualified and experienced the evaluator, the more convincing the results will be.
- In particular, this evaluation requires the intervention of a minimum number of 5 experts in HMI interface ergonomics. However, it is not always easy to find experienced professionals specialized in this discipline.
- These heuristics give better results when they are performed in parallel by a team of evaluators. This is not always possible, especially for companies that are constrained by a lack of resources and a reduced budget.
- The unreliability of this method, due to "false alarms" that can bias the credibility of the evaluation. This may result from overestimating the actual number of usability problems. In addition, heuristics are often elaborated in a rather vague manner, which can lead to unspecific recommendations.
- This approach does not propose solutions to the problems encountered.
- This evaluation is not complete enough, as it cannot detect certain problems related to the development of the digital device.
- The heuristic evaluation may reveal problems that are not part of the evaluation grid.
User Centric Design (UCD) places the user at the center of the design approach objectives. To this end, the evaluator must use ergonomic criteria to uncover interface problems that prevent the system from providing an optimal user experience and that create a sense of dissatisfaction among the user.
The User-Centered Design Process
Here are the good practices to adopt in order to keep the human-centric dimension during a heuristic evaluation :
- To increase knowledge of the target. To this end, the target needs to be specified and segmented, using refined categories into sub-categories. This sampling can be carried out according to criteria: demographic, professional, geographic, physical, etc.
- Create personas. Developing templates for target users allows the evaluator to understand the profile of the target core, for whom the product is intended. This helps the evaluator understand the usability issues he or she needs to identify in particular or first. To do this, it is necessary to develop personas containing all the details of interest for the evaluation. For example, for a travel booking web application, it is relevant to present him/her with personas containing this information: age, identity, gender, marital status, occupation, nationality, number of children, etc.
- Create user scenarios. These scenarios illustrate the context in which the product is used and help the evaluator understand the user's motivations, expectations, and behaviors for using the product and the potential difficulties he or she may encounter when interacting with the system.
- Create prototypes based on customer knowledge built up from UX research (or user research).
Heuristic evaluation is a flexible inspection method that does not consume material and human resources. It is simple to perform and offers a good cost/benefit ratio.
The scope of this evaluation method is very broad and includes as many criteria as there are users. In particular, Colombo & Pasch's 10 criteria aim to use UX heuristics derived from the psychological theory of flow, in order to create an excellent user experience. This type of inspection is used both for auditing and designing interactive systems.
In order to optimize and refine the UX design project, it is relevant to use the Capian tool. It is the solution for moving more quickly to the production cycle and anticipating potential errors that may arise during product development.
For any additional information, do not hesitate to schedule a demo with one of our experts!