The AAAI 2006 conference paper Gigerenzer & Brighton (2009) cite for the take-the-best reversal does not itself contain the city-population reanalysis

rationalityecological-rationalitytake-the-bestcross-validationgigerenzerbrightoncitation-provenanceargument-from-silence

claim-brighton-2006-reanalysis-reversed-take-the-best-result-against-chater-oaksford records, from Gigerenzer & Brighton's 2009 "Homo Heuristicus," that "Brighton (2006)" reanalyzed Chater, Oaksford, Nakisa & Redington's 2003 city-population test of take-the-best using cross-validation instead of fit-then-test-on-the-whole-sample, reversing the verdict: "The predictive accuracy of take-the-best exceeded that of all rival models over the entire range of sample sizes (Fig. 2)." The citation given for this is a specific, page-bounded document: Henry Brighton, "Robust Inference with Simple Cognitive Models," AAAI Spring Symposium 2006, pp. 17–22.

A direct read of that exact paper finds no city-population task, no mention of Chater, Oaksford, Nakisa, or Redington anywhere in its text or twenty-six-item reference list, and no four-panel comparison figure matching the "Fig. 2" Gigerenzer & Brighton describe. The AAAI paper's own cross-validation analysis covers eight different, unrelated regression environments instead: "Figure 1(A) depicts predictive accuracy, estimated using CV, of the six models in eight natural environments as function of sample size" — Biodiversity, ProfessorSalary, Bolts, Oxidants, Obesity, FuelConsumption, Mortality, and Zoo. The paper attributes its underlying dataset to "a larger study (Brighton 2006)," and its own bibliography separately lists "Brighton, H. 2006. Ecologically rational inductive inference. Manuscript in preparation" — so even within the AAAI paper, "Brighton 2006" is not self-identical; it points past itself to at least one other 2006 document.

This does not make the reversal claim false — cross-validation beating fit-then-test is the same mechanism the AAAI paper does demonstrate, just on different data — only that the specific citation offered for the city-population reversal does not resolve to the analysis it is credited with, on direct inspection. This sharpens the open flag on the existing claim: the one-sidedness it already records (Gigerenzer/Brighton narrating their own reversal) is compounded by a citation gap.