The concept of number emerges from the interaction of psychological, behavioral, and material elements of numerical cognition, collapsing the distinction between "abstract" and "concrete." This dual nature is evident in the Inca numerical system, where tools like the yupana integrate abstract numerical concepts with concrete…

This article introduces this special issue of "Frontline Learning Research." The first paper offers a methodological guide using Ericsson & Smith's (1991) "expert performance approach." This is followed by three papers that analyze the use of eye tracking in visual expertise models, and a paper reviewing the use of methods…

We argue that there is an increasing reliance on analytic strategies compared to visuospatial strategies, which is related to geometry expertise and not on individual differences in cognitive style. A Visual/Analytic Strategy Test (VAST) was developed to investigate the use of visuo-spatial and analytic strategies in geometry in 30 mathematics…