Organizations, be they companies, governmental or non-governmental bodies or even associations, manage their projects on the basis of the value of indicators that are obtained automatically or filled in by the various project stakeholders, including the project managers. In this paper, we experimentally study the effect that employees' motivation can have on the data collection process related to project management. By sending two different types of email messages to 177 project managers in a large engineering company, one using the classic corporate format, the other mentioning an academic research objective on the subject, using a somewhat more leisurely presentation style and asking only for volunteer participation, we quantitatively assess the impact of the type of stimulus (one relying on extrinsic motivation, the other, intrinsic) on the overall data collection process. Our results suggest that the type of incentive has no significant effect on the amount of data collected. However, we note a significant effect on the way in which project performance is qualified according to the type of stimulus. In particular, the evaluation of the company's maturity with regard to projects or their 2 EURAM 2022 success is significantly different depending on the stimulation mode. We were thus able to quantify the extent of the differences induced by the employees' motivation, extrinsic or intrinsic. The results obtained confirm the difficulty of characterizing project performance by means of self-provided indicators by highlighting the effects induced by the context of acquisition of these data.