This part of ISO 9241 introduces the multipart standard on ergonomic requirements for the use of visual display terminals for office tasks, provides guidelines for a user-performance approach and gives an overview of all parts of ISO 9241 currently published and of the anticipated content of those in preparation. The document also provides some guidance on how to use ISO 9241 and describes how conformance to ISO 9241 should be reported. For the purpose of ISO 9241, office tasks are taken to include a wide range of generic text and data processing tasks. Due to the similarity of these activities to tasks performed in other environments, e.g. medical, scientific, telecommunications, control rooms and public access, many of the requirements in ISO 9241 are appropriate to these environments as well. ISO 9241 does not cover electrical safety of VDTs. This is covered by IEC 950. The following terms are definded: user-performance approach, user-performance test.