Bangor et al.: "Determining What Individual SUS Scores Mean: Adding an Adjective Rating Scale"

Bangor, A., Kortum, P., & Miller, J. (2009). Determining What Individual SUS Scores Mean: Adding an Adjective Rating Scale. Journal of Usability Studies, 4(3), 114-123.

 


 

Introduction

 

Discusses System Usability Scale (SUS; Brooke, 1996). Did a ten year longitudinal study; found high reliability. Questions how SUS score describes product usability (is 50% enough? or 75-100?). DId a pilot study in which academic letter grading system applied instead of percentage (A exceptional, C acceptable)

 

Methods

 

SUS uses 5 pt Likert (SD ->SA)

 

Adjective Rating Scale: (Worst Imaginable to Best Imaginable)

 

Procedure

 

Added Adjective Rating Scale to bottom of same page; filled out immediately after.

 

Results

 

Seems to argue that results statistically significant, but standard deviation is upwards of 10 points (though it would keep in range of grades)

 

Discussion

 

Suggest using as subjective label for mean SUS score, perhaps using in place of SUS, but researchers caution against.

 

Word "ok" too variable.

 

Looking to correlate to letter grades.