upa - home page JUS - Journal of usability studies
An international peer-reviewed journal

How Low Can You Go? Is the System Usability Scale Range Restricted?

Philip Kortum and Claudia Ziegler Acemyan

Journal of Usability Studies, Volume 9, Issue 1, November 2013, pp. 14 - 24

Article Contents


In a partial replication of the experiment, the highest scoring ballot (ballot N), the lowest scoring ballot (ballot A), and the ballot representing the mid-point SUS score (ballot J) were re-run through an identical protocol. Thirty new participants from the same population that participated in the first study made up the sample. As before, the ballots were administered in a random order. Participants voted with a ballot and then rated it using the Modified SUS. This process repeated until participants voted using all three ballots. As can be seen in Figure 7, the results from this study are nearly identical to those found in the primary study.

Figure 7

Figure 7. Mean SUS score comparison for the first study and the partial replication with error bars representing the 95% confidence interval


Previous | Next