Checkosky, S. F. & Whitlock, D. (1973). Effects of pattern goodness on recognition time in a memory search task. Journal of Experimental Psychology, 100(2), 341-348.

Four factors were varied in a memory search task and their effects on mean reaction time (RT) were evaluated. The factors were (a) pattern goodness of test stimuli and memory set items as defined by reflection-rotation equivalence set size (after a 1963 study by Garner and Clement); (b) discriminability (perceptual clarity) of the test stimuli; (c) the similarity of the test stimuli which require a no response to the memory set items (similarity). The joint effect of pattern goodness and stimulus discriminability was additive. This was interpreted as evidence that the time to form an internal representation of the test stimulus is not influenced by the goodness of the stimulus. At the same time the effect of pattern goodness on RT interacted with memory load. This was interpreted as evidence that the time to generate a visual representation of the memory set items is influenced by the goodness of these items. A significant Pattern Goodness x Similarity interaction was also obtained. This was interpreted in terms of differences in the metric for similarity between good and bad patterns. Further, such an interaction suggests that pattern goodness influences the time to compare the test stimulus with the memory set items.