Effect of item arrangement on perceived numerosity: randomness vs regularity.
Subjects were shown pairs of dot patterns, a regular one and a randomly arranged set, and were asked to say which appeared more numerous. In three experiments using 53 college students regular patterns appeared significantly more numerous than random arrays, with an average illusion of 5.5%. The results were discussed in relation to the breakdown of conservation of number.
D000367:Age Factors; D005556:Form Perception; D006801:Humans; D007088:Illusions; D009903:Optical Illusions; D009949:Orientation; D013028:Space Perception