In the quest for quantitative and qualitative parameters that would characterize the differences (or similarities) in human actions in the real and virtual world, Fink, Foo, and Warren present a study of human performance in obstacle avoidance. In an immersive virtual environment, these researchers find that there is a small but significant difference in the locomotion paths in the two environments. The experiments were carried out in matched real and virtual environment pairs, and the research concludes that the path deviation and the obstacle are larger, and the motion slower, when the subject performs in the virtual environment. The paper attempts to discuss the possible reasons for these phenomena; however, it reassures us that we can comfortably use virtual environments in the study of locomotor behavior.

This must-read paper is an example of research at its best. Not only are the results relevant, but the paper is immaculate in terms of its style, presentation, and correctness. It presents theory, results, and comments in a well-balanced way, and it triggers reflection on a variety of related topics.