What is System Usability Scale

U-Learning environments collects context information relative to user's preferences and needs, but this information is typically very volatile. For this reason, Quality of Context is aimed at treating this information by applying quality parameters. This chapter aims to help the reader understand how the quality of context information can be treated in U-Learning environments, which are the main theoretical bases, technologies that support them and what are the methods, advantages and disadvantages related to this approach. In addition, specific cases of development and application of technologies and strategies involving Quality of Context are presented to illustrate all the concepts described. The results of usability testing related to the SUS questionnaire showed that the developed environment described in the case of study operated satisfactorily, based on the assessments made by the group of users who tested the modules and their operation.