This paper compares three interactive techniques for two-user collaborative manipulation in virtual environments. The first technique averages positions and orientations provided by users (Mean technique). The second technique (DOF separation) splits degrees of freedom of the manipulated object among users. The third technique is a tangible device grasped simultaneously by the two users.We have conducted an experiment where participants were asked to manipulate and assemble, in a collaborative manner, virtual parts. Our results suggest that the mean technique leads to faster completion time probably due to smaller physicalmotions. However, the tangible device seems globally preferred by users in terms of immersion and realism of the task.