A carefully designed experiment pipeline corrupted by context leaks at two nodes, contrasted with the clean rebuilt version

The Experiment Design Was Fine. The LLM Still Failed.

Series: AI Agent Experiment Methodology (Part 2) Part 1: How to Use Double-Blind Experiments to Validate Skill Changes TL;DR: Round one of the double-blind experiment: B won 3/4 scenarios but failed the magnitude filter. Verdict: “insufficient evidence.” Investigation revealed S1-A’s output was polluted by terminal color codes, and the scorer diligently scored 8 dimensions on ANSI garbage. After reconstructing the execution context, B won 4/4. The failure wasn’t in the experiment design—it was in how sub-agents’ context boundaries were constructed. ...

2026-05-31 · 6 min · Alex Wang