Judgment of Volume from Photographs of Complex Shapes

Observers were asked to judge the volume reduction of 40 distorted metal containers from photographs. Hypotheses regarding the role of amount of information provided by photographs, complexity of damage to the container, past experience of the observer, and memory for visual forms were tested in a study using 279 college students. Findings revealed judgment accuracy to vary as a complex function of angular disparity between photographs, number of photographs, type of object, stimulus characteristics of individual containers, and degree of distortion. Volume reduction of “square” objects was judged more accurately than that of “round” objects. Individual observers were found to be reasonably consistent from one type of object to another in over- or underestimating volume reduction.