aj_jaggedness_penalty
A Model of Artificial Jagged Intelligence — Joshua S. Gans (arXiv:2601.07573, 2026)
What this evaluates
Proposes a diagnostic metric to quantify the discrepancy between macro-averaged benchmark scores and experienced reliability in deployment. It accounts for uneven task coverage by measuring the dispersion of error rates across domains, highlighting how gap-uniform evaluation can misstate actual user experience.
Datasets
- (no dataset; pure metric skill)
Metrics
CV_d(e_d)(primary) — range: other- Coefficient of variation of domain-level error rates, calculated as sqrt(Var(e_d))/E[e_d], where e_d = 1 - s_d. Used as a diagnostic for the inspection wedge between benchmark averages and experienced reliability.
Input / output format
Input: Per-domain benchmark scores s_d(m) and domain-level error rates e_d = 1 - s_d.
Output: A single dispersion statistic (CV_d(e_d)) or a deployment-weighted score S^dep(m).
Scoring recipe
def compute_jaggedness_penalty(scores_per_domain):
errors = [1 - s for s in scores_per_domain]
mean_err = sum(errors) / len(errors)
var_err = sum((e - mean_err)**2 for e in errors) / len(errors)
return (var_err ** 0.5) / mean_err
Common pitfalls
- Assuming macro-averaged benchmark scores reflect deployment reliability without checking domain exposure distribution.
- Treating long-tail benchmarks like BIG-bench as representative of average-case performance rather than tail-risk modules.
Evidence (verbatim from paper)
If only an unweighted or uniform-weight benchmark is available, one can report a dispersion statistic across domains, such as CV_d(e_d) for domain-level error rates e_d ≡ 1-s_d. In settings where domain size and domain error are positively associated (the AJI mechanism), CV_d(e_d) is informative about how far the macro-average can drift from experienced reliability.
Citation
@misc{gans2026model,
title={A Model of Artificial Jagged Intelligence},
author={Joshua S. Gans},
year={2026},
note={arXiv:2601.07573}
}
- arXiv: 2601.07573