The tension
Diversity is useful because it preserves options. Bloat is harmful because it consumes memory, evaluation time, and human attention. A model ecology needs enough diversity to adapt, but not so many artifacts that no one can explain the active set.
The distinction is contribution. Useful diversity covers a different domain, failure mode, style, latency tier, privacy boundary, or hardware target. Bloat duplicates capability without enough benefit.
Diversity measurements
| Measure | What it detects | Caveat |
|---|---|---|
| task coverage | which tasks have competent specialists | may miss rare failures |
| disagreement rate | whether models produce meaningfully different outputs | disagreement can be noise |
| embedding distance | representation variety | may not map to behavior |
| lineage distance | different parents/operators | distant lineage can still duplicate behavior |
| route utilization | whether the router actually uses a model | rare paths may still matter |
| marginal viability | contribution after cost | depends on weights |
Retirement pressure
Every active specialist should have a reason to remain loaded, deployable, or archived. Retirement does not mean deletion. It means the model leaves the active route set and becomes evidence or rollback material.
PROCEDURE prune_bloat(ecology, policy)
FOR each model IN ecology.active_models
contribution <- MEASURE_MARGINAL_CONTRIBUTION(model, ecology)
cost <- MEASURE_ACTIVE_COST(model)
rarity <- MEASURE_RARE_CASE_COVERAGE(model)
IF contribution < policy.min_contribution AND rarity < policy.min_rare_coverage
MARK_FOR_RETIREMENT(model, reason = "low marginal value")
END IF
END FOR
APPLY_RETIREMENTS_THROUGH_CANARY(ecology)
END PROCEDUREQuality-diversity rule
Do not keep diversity for its own sake. Keep high-quality representatives for meaningful niches. When two models cover the same niche, prefer the one with better calibration, lower cost, cleaner provenance, and easier rollback.
Operational cadence
Run bloat review on a schedule. If the ecology only prunes during emergencies, retirement becomes politically or emotionally difficult. Normal pruning keeps the system governable.
Source reports used for this guide
These reports are preserved verbatim in the site archive. The guide above is an editorial synthesis and may narrow, qualify, or reorganize claims from the source material.