“Points-of-View” analysis has been promoted as an appropriate analysis for similarity data collected with the Method of Sorting. It can be regarded as an extension of Cultural Consensus Analysis. The latter assumes that subjects all base their responses on a single shared ‘model’ of the items to be sorted. Conversely, the titular “points-of-view” are multiple models, sampled singularly by some subjects’ responses, while other subjects combine the models in various proportions. The analysis appears to be comparatively insensitive to the artefacts (...) to which sorting data are prone, which affect how easily they can be interpreted with multidimensional scaling. Here we apply the Points-of-View approach to two sets of data from the colour domain, a sensory modality well-suited for the sorting procedure. One study extracted three viewpoints – i.e., factors, prototypal ways of organising the stimuli – with one viewpoint specific to colour-vision-deficient observers, capturing independently-measured differences among the subjects. In the second study, two viewpoints proved to be appropriate: one arranged the items by two dimensions, lightness/saturation as well as hue, while the second was essentially a one-dimensional hue-based arrangement. This distinction could not be recovered from the raw data by applyingmdswith the weighted-Euclidean model of individual difference. We discuss some demographic factors which might dispose subjects to attend to hue only or saturation/lightness as well. (shrink)

This paper studies the learnability of natural concepts in the context of the conceptual spaces framework. Previous work proposed that natural concepts are represented by the cells of optimally partitioned similarity spaces, where optimality was defined in terms of a number of constraints. Among these is the constraint that optimally partitioned similarity spaces result in easily learnable concepts. While there is evidence that systems of concepts generally regarded as natural satisfy a number of the proposed optimality constraints, the connection between (...) naturalness and learnability has been less well studied. To fill this gap, we conduct a computational study employing two standard models of concept learning. Applying these models to the learning of color concepts, we examine whether natural color concepts are more readily learned than nonnatural ones. Our findings warrant a positive answer to this question for both models employed, thus lending empirical support to the notion that learnability is a distinctive characteristic of natural concepts. (shrink)

The origin of colour categories and their relationship to colour perception have been the prime example for testing the influence of language on perception and thought and more generally for investigating the biological, ecological and cultural determination of human cognition. These themes are central to a broad range of disciplines, including vision research, neuroscience, cognitive psychology, developmental science, cultural anthropology, linguistics, computer science, and philosophy. Unfortunately, though, it has been tacitly taken for granted that the conceptual assumptions and methodological practices (...) from the dawn of empirical research on colour categorisation are the gold standard for current colour category research. Here, we show that these assumptions and practices are obsolete and flawed and have led to four fundamental and widespread misconceptions about colour categorisation: 1.) that colour perception is inherently categorical; 2.) that English Basic Colour Terms correspond to universal categories that are the end point of a fixed evolutionary sequence; 3.) that the prototypes of English basic colour terms are perceptually salient and qualify as focal colours; and 4.) that colour category research essentially revolves around the universalism-realism debate. State-of-the-art research on colour categorisation provides new, more sophisticated approaches and allows for rectifying those four statements. At the same time, some of the questions underlying those statements are not convincingly answered yet and constitute major challenges to future research. The critical considerations on colour categorisation may be transferred to research on other kinds of perceptual categorisation to inspire new, more general research questions. (shrink)