Table 3.
Results from the System Usability Scale
| Item no. | Item | Session | Rating group A Mean (SD) | Rating group B Mean (SD) | Rating all Mean (SD) |
|---|---|---|---|---|---|
| Q1 | I think that I would like to use this system frequently. | 1 | 3.0 (1.4) | 3.3 (1.5) | 3.1 (1.4) |
| 2 | – | 3.2 (1.2) | – | ||
| I (did not) find the system unnecessarily complex. | 1 | 3.0 (0.7) | 4.3 (0.8) | 3.4 (0.9) | |
| 2 | – | 3.6 (0.8) | – | ||
| Q3 | I thought the system was easy to use. | 1 | 3.0 (1.2) | 3.3 (1.1) | 3.1 (1.1) |
| 2 | – | 3.6 (1.0) | – | ||
| I (do not) think I would need the support of a technical person to be able to use this system. | 1 | 2.8 (1.2) | 2.3 (1.6) | 2.6 (1.4) | |
| 2 | – | 2.2 (1.5) | – | ||
| Q5 | I found the various functions in this system were well integrated. | 1 | 3.4 (1.0) | 4.3 (0.8) | 3.7 (1.0) |
| 2 | – | 3.2 (1.5) | – | ||
| I (did not) think there was too much inconsistency in this system. | 1 | 3.3 (0.8) | 4.5 (0.5) | 3.7 (0.9) | |
| 2 | – | 4.0 (0.6) | – | ||
| Q7 | I would imagine that most people would learn to use this system very quickly. | 1 | 4.0 (0.9) | 4.5 (0.5) | 4.2 (0.9) |
| 2 | – | 3.8 (1.0) | - | ||
| I (did not) find the system very cumbersome to use. | 1 | 2.9 (1.1) | 3.5 (1.1) | 3.1 (1.1) | |
| 2 | – | 3.0 (0.9) | – | ||
| Q9 | I felt very confident using the system. | 1 | 3.3 (1.2) | 4.3 (0.4) | 3.6 (1.1) |
| 2 | – | 4.2 (0.4) | – | ||
| I (did not) need to learn a lot of things before I could get going with this system. | 1 | 3.9 (1.0) | 3.8 (1.3) | 3.8 (1.1) | |
| 2 | – | 4.2 (1.2) | – | ||
| 1 | 56.7 (17.2) | 69.4 (15.2) | 60.6 (17.7) | ||
| Total score | 2 | – | 62.5 (8.9) | – |
The statements for the even items are inverted to make all points positive (indicated with the parentheses) and the scoring for these items was adapted accordingly
Mean and standard deviation for each item rating and the overall SUS scores are reported for group A (P1–P10), for group B (P11*–P15*) and across all participants (P1–P15*). Item ratings range from 1 (completely disagree) to 5 (completely agree) and total scores range from 0 to 100, where a higher value corresponds to better usability. (*: Group B; : inverted item; SD: standard deviation)