From cafc1c89be428ce1023240f2d310c12632326647 Mon Sep 17 00:00:00 2001
From: wassname <1103714+wassname@users.noreply.github.com>
Date: Wed, 26 Aug 2026 14:16:25 +0800
Subject: [PATCH] SKILL.md: quote Sanh on the threshold mistake, the one bullet
 left bare

---
 SKILL.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/SKILL.md b/SKILL.md
index cb3e76e..7f3246a 100644
--- a/SKILL.md
+++ b/SKILL.md
@@ -66,6 +66,10 @@ easy to make a mistake with cosine. It is not causal, and two different subspace
 even when they are correlated, so `cos(apple, orange) = 0` is not a null result. Building the real
 thing and running it takes longer and answers the question. Exercise 2.
 
+> *   How would a random predictor perform (especially in classification problems)? Dataset can be unbalanced...
+> *   What would the loss look like for a random predictor?
+> *   What are the limits of this metric? If it's perfect, what can I conclude? What can't I conclude? -- Sanh
+
 Do not fix on an arbitrary metric threshold before you have any idea what a fair or good threshold
 is. Saying the metric must clear 0.8 means nothing until you know what counts as good here. Get the
 scale first, from a null arm and a shuffled control. Exercise 15.