The evaluation of trial results for a voice activated telephone intermediary system

We developed an experimental voice activated telephone intermediary system in 1993. It is intended to accept the caller´s message and to transfer the call to an appropriate number according to the callee´s schedule and the callee´s setting of services. A caller can use such services by speaking his name, callee´s name, confirmation words, his phone number, and his message, in that order, in response to system prompts. An experiment was conducted using 11 callees, laboratory researchers. 139 calls were logged within the 22 day experiment. System usage ratio and service completion ratio were 53 percent and 86 percent, respectively. The paper describes the experiment and it´s results, and discusses the dialog designs that minimize recognition error and encourage callers to start/continue to use the system