Beck (1972) pointed out that grouping tasks, where one set of elements is distinguished from another, do not imply associative links within either set of elements but could rely on processes of segregation. Although many physiological theories of grouping are purely associative there are not many methods of isolating associative processes psychophysically. One method has been to measure common resolutions of elements when they are presented under conditions of depth and motion ambiguity. In the present paper a number of the issues surrounding grouping are considered, particularly in relation to associative processes. These include whether grouping is post-constancy and post-completion, grouping with and without emergent features, the role of top-down processing and attention and the explanatory role of general principles such as simplicity and likelihood.