Systèmes d'Information et Management


The level of use of an information system is a valid method of evaluation of its success. It is unclear, however, which one of the subjective and the objective measures should be prefered over the other. An empirical study was conducted to conclude that users over estimated their usage of an electronic mail system by an average of 45 % when the evaluation was based on a self-reported measure. Therefore, it is concluded that objective measures of information system use should be used for management control purposes. For both types of measures, the perceived consequences of usage and the social factors associated with usage were the main predictors of use.