Title: LORE: Jointly Learning The Intrinsic Dimensionality and Relative Similarity Structure from Ordinal Data
Primary area: applications to neuroscience & cognitive science
Keywords: Ordinal Embedding, Intrinsic Dimensionality, Psychophysics, Subjective Perceptual Learning, Relative Similarity Embedding

Abstract: Learning the intrinsic dimensionality of subjective perceptual spaces such as taste, smell, or aesthetics from ordinal data is a challenging problem. We introduce LORE (Low Rank Ordinal Embedding), a scalable framework that jointly learns both the intrinsic dimensionality and an ordinal embedding from noisy triplet comparisons of the form, "Is A more similar to B than C?". Unlike existing methods that require the embedding dimension to be set apriori, LORE regularizes the solution using the nonconvex Schatten-p quasi norm, enabling automatic joint recovery of both the ordinal embedding and its dimensionality. We optimize this joint objective via an iteratively reweighted algorithm and establish convergence guarantees. Extensive experiments on synthetic datasets, simulated perceptual spaces, and real world crowdsourced ordinal judgements show that LORE learns compact, interpretable and highly accurate low dimensional embeddings that recover the latent geometry of subjective percepts. By simultaneously inferring both the intrinsic dimensionality and ordinal embeddings, LORE enables more interpretable and data efficient perceptual modeling in psychophysics and opens new directions for scalable discovery of low dimensional structure from ordinal data in machine learning.

TL;DR: LORE jointly infers both the intrinsic dimensionality and an ordinal embedding from noisy triplet comparisons, enabling compact, interpretable perceptual representations from purely ordinal data.