Table 3.
System Usability Scale | Mean score | Positive response, n (%) |
---|---|---|
µ ± SD | ||
I think that I would like to use this service frequently. | 4.0 ± 0.4 | 85 (93.4) |
I found the service unnecessarily complex | 1.9 ± 0.6 | 3 (3.3) |
I thought the service was easy to use | 4.0 ± 0.4 | 80 (87.9) |
I think that I would need the support of a technical person to be able to use this service | 2.0 ± 0.5 | 3 (3.3) |
I found the various function in this service were well integrated | 3.7 ± 0.6 | 74 (81.3) |
I thought there was too much inconsistency in this service | 2.0 ± 0.5 | 2 (2.2) |
I would imagine most people would learn to use this service very quickly | 3.8 ± 0.5 | 73 (80.2) |
I found the service very cumbersome to use | 1.9 ± 0.5 | 15 (16.4) |
I felt very confident using the service | 3.9 ± 0.5 | 91 (89.0) |
I needed to learn a lot of things before I could get going with this service | 2.2 ± 0.8 | 11 (12.0) |
aScores for individual questions range from 1 = Strongly disagree to 5 = Strongly agree. To compute the total SUS score for each respondent, we first converted the score for each question to a range from 0 to 4, with scores of 3 and 4 considered positive responses, and 4 being the most positive response. To do this, for all odd-numbered questions, which were positively worded, we subtracted 1 from the user response, and for even-numbered items, which were negatively worded, we subtracted the user response from 5. We then added up the converted responses for each user and multiplied that total by 2.5. This scaled the range of possible values from 0 to 100 instead of from 0 to 40, with each question weighing 10 points