Measuring spatial factors in comparative judgments about large numerosities

Abstract

Numerical information is crucial to successful performance on many tasks. Accordingly, as a basis for developing augmented cognition applications, it is important to understand how people apprehend numerical information and whether there are systematic limitations on their ability to do so accurately. This paper reports research on the role of non-numerical spatial information and of numerical representations in adults' judgments about large-numerosity spatial arrays. Arrays that contained more open space tended to be perceived as less numerous than ones with less open space. Further, the accuracy with which viewers estimated the arrays' numerosities bore little relation to their success in identifying the more numerous array in each pair. Numerical judgments thus are heavily influenced by spatial information that is not necessarily a reliable cue to numerosity. While some information about absolute numerosity is extracted in making numerical comparisons, it appears to be very imprecise. © Springer-Verlag Berlin Heidelberg 2007.