MachineSex/results/E4/README.md
Giorgio Gilestro 3b9f4f7893 docs: accessible figure legends (README.md) for all figures
One self-contained README.md per results/ figure folder (Layer 1 E1-E6
and Layer 1.5 bridge/collapse/grounding/architectures/recombination):
plain-language claim, setup, a compact symbol glossary, a panel-by-panel
walkthrough, and the takeaway + falsifier. Auto-renders when browsing the
folder; carries the honest caveats (grounding's ruler reframing, the
excluded VAE).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-05 08:43:04 +01:00

33 lines
2.5 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# E4 — Recombination supplies the rare tail; only a union-preserving *merge* realises it
**Claim tested:** if several specialist models each remember a different slice of the rare tail, can
combining them reconstruct the whole tail? And does *how* you combine them matter?
**Setup (Layer 1, pure math).** `K = 500` items. We build `K_T` teacher models that each retain the
rare tail with probability `q`, and we control how **correlated** their retained tails are with a
single knob `ρ` (rho): `ρ = 0` = fully complementary teachers, `ρ = 1` = identical teachers. Swept:
`K_T ∈ {1,2,3,5}`, `ρ ∈ {0, 0.25, 0.5, 0.75, 1}`, grounding `g ∈ {0, 0.02, 0.05}`, 200 repeats.
### Symbols
- **`K_T`** number of teacher models; **`ρ`** how correlated their retained tails are (0 = diverse, 1 = clones).
- **union coverage** — fraction of the tail covered by *at least one* teacher (the raw supply).
- **surviving coverage** — fraction that actually survives in the pupil after it retrains on the combination.
- **mean-distill** — pupil trained on the pooled/averaged teacher outputs. **max-merge** — keep, per item, the strongest teacher (a union-preserving merge, à la M2N2).
### The three panels
1. **Supply.** Union tail coverage vs `ρ`, one curve per `K_T`; solid lines are the exact closed form
`U(K_T, ρ, q)`. More teachers and more diversity (lower `ρ`) supply more of the tail — and the
simulation matches the formula exactly.
2. **Realisation.** Surviving coverage vs `ρ`. **Solid = max-merge rises** with more/diverse teachers;
**dashed = mean-distill stays flat.** Averaging dilutes each teacher's rare items back below the
survival threshold — the gain is supplied but not realised.
3. **The benefit needs the right operator (`ρ = 0`).** Surviving coverage vs `K_T` under both
operators. Max-merge climbs with teacher count; mean-distill is flat — a **conservation law**:
averaging's `1/K_T` dilution exactly cancels the union gain.
### Takeaway — "merge, don't average"
Complementary specialists *contain* enough to rebuild the tail, but **naive multi-teacher distillation
(averaging) throws it away**; you must combine them with a union-preserving merge. This is load-bearing
for the paper's recombination claim and is re-tested in real neural weights in `results/recombination/`.
**Falsifier (not triggered):** if mean-distill had also risen with `K_T`, or max never beat mean, the
recombination story would collapse into "just average your models."