Eye height scaling of absolute size in immersive and nonimmersive displays

Eye-height (EH) scaling of absolute height was investigated in three experi ments. In Experiment 1, standing observers viewed cubes in an immersive vir tual environment. Observers' center of projection was placed at actual EH a nd at 0.7 times actual EH. Observers' size judgments revealed that the EH m anipulation was 76.8% effective. In Experiment 2, seated observers viewed t he same cubes on an interactive desktop display; however, no effect of EH w as found in response to the simulated EH manipulation. Experiment 3 tested standing observers in the immersive environment with the field of view redu ced to match that of the desktop. Comparable to Experiment 1, the effect of EH was 77%. These results suggest that EH scaling is not generally used wh en people view an interactive desktop display because the attitude of the c enter of projection is indeterminate. EH scaling is spontaneously evoked, h owever, in immersive environments.