Users tend to attribute human qualities to personified user interfaces. There are few guidelines for the design of effective personified user interfaces. In general, you should avoid personified user interfaces (applications in which the system has a name) unless there is a compelling reason to build one. When designing a persona, be user centered, not machine centered. No matter what you do, users will perceive your system as having a personality, so you should deliberately design your system to have a personality appropriate for the application. For applications that have self-service and call-routing functions, you will usually want a professional persona. You will also want the persona to be consistent with the client company's brand and other aspects of corporate image.