Methods of usability testing for users with cognitive impairments One challenge of the user centered development of accessible information systems is the conduction of cognitively impaired persons in usability tests. The paper gathers existing guidelines for the application of usability testing with cognitively impaired people and shows empirical values for modified usability tests based on a case study. In addition the advantages and disadvantages of on site and remote usability testing are presented in a comparative study. Especially in the context of COVID 19 remote testing has gained in relevance in the present time.