Australasian Mathematical Psychology Conference 2019

The cost of errors: Confusion analysis and the mental representation of numerals

Ami Eidels
University of Newcastle
Murray Bennett
University of Newcastle
Paul Garrett
University of Newcastle

People express quantities via numbers, using a remarkably small set of only ten basic units – digits. Confusing digits could be costly, and not all confusions are equal; confusing a price tag of 2 dollars with 9 dollars (or 2 million vs 9 million, for a more dramatic effect), is naturally more costly than confusing 2 with 3. Confusion patterns are intimately related to the distances between mental representations, which are hypothetical internal symbols said to stand for, or represent, ‘real’ external stimuli. The distance between the mental representations of two digits could be determined by their numerical distance. Alternatively, it could be driven by visual similarity (or by some other properties). We investigated the mental representations of familiar and unfamiliar numerals (4 sets: Arabic, Chinese, Thai, and non-symbolic dots) in a set of identification experiments, using Multi Dimensional Scaling and Cluster Analysis. We controlled for undesired effects of response bias using Luce’s choice model.