User participation is defined as the extent to which users or their representatives carry out assignments and perform various activities and behaviors during the system development process. This work has identified three dimensions of user participation: responsibility, the user-IS (information system) relationship and hands-on activity. However, this 3D view of user participation does not capture an important aspect of participation: the communication between users and with various stakeholders. This paper replicates and extends past research by proposing the addition of a fourth dimension: communication activity. Data collected from 324 users drawn from 162 IS development teams were used to replicate our three dimensions and to examine evidence for the construct validity of the new dimension. Consistent with expectations, strong evidence was found suggesting that communication activity needs to be considered as a fourth dimension of user participation.