When a digital learning platform is designed for adults aged 55 and over, usability is not just a technical concern — it is central to whether the platform works at all. If people find a system confusing, frustrating, or difficult to navigate, they are unlikely to engage with it, regardless of how strong the content may be. This is why the BonJour! Project team chose to evaluate the platform using one of the most established methods in the field: the System Usability Scale, or SUS.
What is the System Usability Scale?
The SUS is a standardised questionnaire that has been used in usability research for decades. It consists of ten short statements about a system — covering aspects such as ease of use, consistency, learnability, and user confidence. Participants respond on a five-point scale, ranging from “strongly disagree” to “strongly agree”. The responses are then converted into a single score between 0 and 100.
Scores above 68 are considered above average. Scores above 80 indicate very good usability, and scores approaching or exceeding 90 are regarded as excellent — placing a system in the top tier of comparable digital tools.
How the evaluation was carried out
A total of 30 participants took part in the evaluation across five modules of the BonJour! platform. The questionnaire was administered in German, maintaining the language of the training programme. After completing each module, participants answered the ten SUS questions, allowing the team to assess usability not just for the platform as a whole, but for each module individually.
What the results show
The results are encouraging across the board. The overall mean SUS score for the platform was 84.8 out of 100, placing it firmly in the “very good” range and close to the threshold that benchmarks describe as excellent.
Looking at the individual modules, a clear pattern emerges. Module 1 — the entry point to the course — achieved a score of 76.3. While this is still a good result, it is the lowest of the five modules. This is not surprising: first encounters with a new platform often require more orientation, and users naturally need some time to familiarise themselves with the structure and navigation. The scores then rise consistently, with Module 2 reaching 83.3, Module 5 84.2, and Module 4 an impressive 89.6.
The standout result belongs to Module 3 — Analyse! Truth? — which achieved a mean SUS score of 91.9. This places it in the “excellent” category and suggests that the module’s design, structure, and interaction flow were particularly well received. It represents a best-practice example within the course and offers useful insights for further development of other modules.
What participants said, in numbers
At the level of individual questionnaire items, participants rated the platform particularly highly for ease of use, the quality of integrated functions, and how quickly they were able to learn to use the system. User confidence while navigating the platform was also notably high. Minor variation appeared in responses related to the need for technical support and the perception of consistency — areas that are worth monitoring in future iterations, though they do not indicate any systematic problem.
What this means in practice
A SUS score of 84.8 is a strong result for any digital platform. For a learning tool aimed specifically at adults who may have varying levels of digital experience, it is particularly meaningful. It suggests that the BonJour! platform is accessible, intuitive, and well-structured — and that most users can engage with it without significant barriers.
Usability of this standard supports not only a positive user experience, but also the educational goals of the project. When a platform is easy to use, learners can focus on what matters: the content, the activities, and the skills they are developing. The BonJour! evaluation results suggest the platform is delivering on that promise.
Further reading: SUS explained simply
The System Usability Scale (SUS) is a short, standardised questionnaire used to measure how easy a system is to use. It consists of ten statements — five positive and five negative — which users rate on a scale from 1 (strongly disagree) to 5 (strongly agree).
The responses are converted into a single score between 0 and 100. This score reflects the overall usability of a system as perceived by its users. It does not measure technical performance, but captures how confident, comfortable, and in control users feel when interacting with the system.
Scores are interpreted against established benchmarks:
- Below 68 — below average; improvements are needed
- 68–79 — good; the system performs adequately
- 80–89 — very good; users find the system largely intuitive
- 90–100 — excellent; the system is considered best-in-class
SUS is widely used in usability research because it is quick to complete, easy to analyse, and produces reliable results even with small groups of participants. It can be applied to any system — digital or physical — and is particularly useful for comparing usability across different versions or modules of a product.