In order to determine ground truth, the researchers recruited an expert in Computational Fluid Dynamics (CFD), the branch of mechanics that the Virtual Wind Tunnel simulation was based on. This expert answered the same questions given to the participants, and the expert’s responses were used as a basis for right answers (ground truth). The participants’ responses were compared to the responses of the expert, and each participant’s score was determined based on the percentage agreement with the ground truth. The average score breakdown of the groups was as follows:

• Master crowd workers: 79.79%
• Non-Master crowd workers: 78.25%
• University One students: 67.91%
• University Two students: 69.04%