The paper in PDF: https://www.pnas.org/doi/pdf/10.1073/pnas.2119753119?download=true https://www.pnas.org/doi/pdf/10.1073/pnas.2119753119?downloa... there’s a l

The paper in PDF: https://www.pnas.org/doi/pdf/10.1073/pnas.2119753119?download=true https://www.pnas.org/doi/pdf/10.1073/pnas.2119753119?downloa... there’s a lot of math symbols but IMO the usage is pretty straightforward for anyone familiar with linear algebra and proofs. Ramsay (30) suggests that the principle of diminishing returns or its opposite may have been spuriously identified by otherresearchers (daringly including his PhD advisor, Helm) because of experimental procedures (successive intervals, paired compar-isons) ill suited to the task. Indeed, open-ended and criterion-dependent tasks give less accurate measures of similarity because of individual factors and the difficulty of the task… Instead, we use a more reliable two-alternative forced choice (2AFC) task, where the participant simply answers the following question: "Which is more different?" Specifically, we use a triad arrangement of stimuli with the reference in the middle and one test on either side. Each of 320 triads covering the neutral axis was judged by at least 250 different participants in a crowdsourced study on Amazon Mechanical Turk (MTurk) (52).* The core of it seems strong, IMO. I would have liked a bit more cognitive science / philosophy to distinguish between an ideal color space and whatever imperfect model is created by individual human’s neural software, and skipping Goethe and Schopenhauer in the intro was downright criminal, but that’s more on me than them. Color has long been a convenient “entry point” into the study of human unconscious and subconscious data transformations, most notably through Wittgenstein’s musings about red squares. I look forward to this technique being extended to other spaces, even ones as abstract as “moral space” or “valence space”!