As part of an Alvey-sponsored project on the human factors of speech system interfaces, users' views of human factor aspects of automatic speech recognition (ASR) were elicited from over thirty sites in the UK and USA. Comments from users and researchers suggested that: a) Many successful applications allow flexibility for the user in vocabulary selection and training; b) The acceptability of systems is aided by offering economy and naturalness of input; c) Recognition rates are currently too low to be acceptable in some critical applications, such as avionics. It was observed that successful applications were generally those where the original task offered a rigid structure, allowing ready application of syntax. The implications of these findings for research on human factors are outlined.