Australasian Mathematical Psychology Conference 2019

Estimating multiple item sets: Harder than you think!

Paul Garrett
Psychology, The University of Newcastle
Zachary Howard
The University of Newcastle
Joe Houpt
Wright State University
David Landy
Indiana University
Ami Eidels
The University of Newcastle

Like many species, humans can perform non-verbal estimates of quantity through our innate approximate number system. However, the cognitive mechanisms that govern how we compare these estimates are not well understood. Little research has addressed how the human estimation-system evaluates multiple quantities, and fewer studies have considered the cost to cognitive workload when undertaking these tasks. Here, we apply the mathematical tools of Systems Factorial Technology to a comparative estimation task. Across a series of experiments, we assess whether quantities, represented by red and blue discs, are estimated simultaneously (in parallel) or sequentially (in serial), and under what restrictions to cognitive workload. Our findings reveal that two item-sets may be estimated simultaneously through a parallel estimation system, under severe restrictions to cognitive workload capacity. These restrictions are not due to the estimation process. The results can be extended to comparisons made with the subitizing range.