This part of ISO 9241 gives guidance on, and requirements for, the user interface design of interactive voice response (IVR) applications. It covers both IVR systems that employ touchtone input and those using automated speech recognition (ASR) as the input mechanism. It is equally applicable to cases in which the caller or the IVR system itself (e.g. in some telemarketing applications) initiates the call. This part of ISO 9241 is intended to be used together with ISO/IEC 13714. NOTE Its scope is thus more general than that of ISO/IEC 13714, which is specific to voice messaging systems.