AUTHORS
Lewis, J. J. R., & Sauro, J.
The Sistem Usability Scale is a standardized questionnaire for the assessment of perceived usability. It consists of 10 items, ranged on a five pointslikert scale: from 1=strongly disagree to 5=strongly agree. It's a mixed-tone questionnaire in which odd numbers items have a positive tone and the even numberes have a negative tone.
REFERENCE
Lewis, J. J. R., & Sauro, J. (2017). Revisiting the factor structure of the system usability scale. Journal of Usability Studies, 12(4), 183-192.
Brooke, J. (1996). SUS-A quick and dirty usability scale. Usability evaluation in industry, 189 (194), 4-7.
System Usability Scale