Design review (DR) is a product development(PD) activity used to inspect the technical characteristics of a design solution.Immersive virtual reality (IVR)technology enables the presentation of spatial information and interaction with 3D CAD models inside an immersive virtual environment (IVE).Such capabilities have shown the potential to mitigate the cognitive load needed for the visual perception of spatial information and,consequently,enhance design understanding and DR performance.Thus,an increasing number of studies have explored the effect of IVR technology on DR activities in different domains.However,determining when the implementation of IVR technology rather than a conventional user interface for DRs in mechanical engineering PD projects will be beneficial remains unclear.Hence,a conceptual DR experimental study was conducted to investigate the differences in the ability of engineering students to identify mechanisms and understand their functions when a design solution for a technical system is presented in an IVE by IVR technology and in a non-immersive virtual environ-ment (nIVE) by a conventional user interface (monitor display,keyboard,and mouse).Data were collected by performing DR tasks and having participants complete a prior experience questionnaire,presence questionnaire,and mental rotations test.Findings of the study indicate that IVR does not support an enhanced ability of engineering students to identify mechanisms and under-stand their functions compared with a conventional user interface.