Food, mammals, & countries: Stimuli, their pairwise similarities, and MDS dimension values for modeling judgment, categorization, and memory in three real-world domains.

Three comprehensive sets of naturalistic stimuli, each with pairwise similarity ratings and multidimensional scaling (MDS)-based feature representations are presented, freely available on the corresponding OSF repository of this project under a CC-BY-SA-NC-4.0 license. The primary contribution of this work is the provision of these well-curated naturalistic stimulus sets and their associated high-quality similarity data as a resource for the research community. The sets include 80 representative items from three domains - foods, mammals, and countries - that can be used across cognitive research areas such as categorization, multiple-cue probability learning, judgment, decision-making, memory, and metamemory. Based on over 280,000 similarity judgments from N = 1798 participants, we derived 14 dimensions for foods, ten for mammals, and ten for countries, which reconstructed the similarity spaces with high accuracy ( r ≥ . 93 ). In a proof-of-concept study, these dimensions also explained substantial variance in participants' numerical judgments of domain-specific criteria, underscoring their functional relevance beyond similarity tasks. By making these stimuli, similarity data, and derived feature spaces freely available, we provide researchers with tools for testing computational cognitive models in relevant real-world domains, each of which allows for examining a multitude of judgment or classification criteria.