Statistical processing: not so implausible after all.

Myczek and Simons (2008) have shown that findings attributed to a statistical mode of perceptual processing can, instead, be explained by focused attention to samples of just a few items. Some new findings raise questions about this claim. (1) Participants, given conditions that would require different focused attention strategies, did no worse when the conditions were randomly mixed than when they were blocked. (2) Participants were significantly worse at estimating the mean size when given small samples than when given the whole display. (3) One plausible suggested strategy--comparing the largest item in each display, rather than the mean size--was not, in fact, used. Distributed attention to sets of similar stimuli, enabling a statistical-processing mode, provides a coherent account of these and other phenomena.