Whether the Pairwise Rating Method and the Spatial Arrangement Method yield comparable dimensionalities depends on the dimensionality choice procedure

We investigate whether the Pairwise Rating Method (PRaM) and the Spatial Arrangement Method (SpAM) yield multidimensional scaling (MDS) solutions of comparable dimensionality. Across three studies that included twelve semantic categories with varying numbers of both pictorial and verbal exemplars, we did not find consistent dimensionality differences between the two similarity measurement methods. The results alleviate the concern that SpAM might underestimate the dimensionality of high-dimensional stimuli compared to PRaM. However, the resulting number of dimensions was found to be highly dependent on the dimensionality choice procedure, indicating the need for a more systematic investigation into dimensionality selection for MDS.