Development and Validation of a Positively Worded German Version of the System Usability Scale: The SUS-DE-Pos

Abstract

Despite its popularity, knowledge of the psychometric quality of the System Usability Scale (SUS) in German is limited. This paper addresses this by developing a positively worded German SUS version and investigating two existing German versions. In a preregistered first study, initial positive alternatives for the negative items were evaluated, and the two German versions were compared. Based on these results, a preregistered second study validated the new positive-only SUS version and independently validated the two original German SUS versions. Results indicated that the SUS-DE-Pos, a positive version based on Rummel (2016), performed best. Researchers are thus advised to use this version. If negative items are needed, for consistency, Rummel (2016)'s version is recommended. Overall, this work provides validated German SUS versions, both with and without negative items, addressing a critical gap for German-speaking HCI researchers and practitioners.