# What is a decision model

A decision model returns a typed answer with probabilities. Methodology v1.0. The crown uses Decision Index Full.

## Typed answers

A decision model takes state, as text or as images, plus a typed question. It returns a typed answer with probabilities rather than free text. Output types: noul (yes/no/unknown), choice, score, multi-label.

Decision models are their own category. They are not folded into General LLM.

## How the crown is decided

Jev Decision Index (https://huggingface.co/spaces/multimodalart/jev-decision-index) is an independent primary. Decision Index Full has weight 1. JevBench (https://benchmarkheaven.com/jev-models/v1.6.1) is a second independent primary. JevBench has weight 1. Open-weight rows use capability. Hosted API rows use the headline composite.

A gap of 1 index point or less is a tie. Tied leaders are co-SOTA and share rank 1. Everyone else is labeled with a best rank.

A later crown needs 2 consecutive snapshots of the same index edition, or 2 independent primary sources agreeing. A new edition is logged as board re-based, and the consecutive snapshot count starts over. A new JevBench revision resets that source the same way.

## Calibration

The calibration slice ranks the lowest ECE among models in the top quartile of accuracy, so a constant probability cannot take the slice. Brier breaks ECE ties.

ECE = Σ w·|accuracy − confidence|. When the index publishes bins, the recomputed ECE must match the published value within 0.002. Vendor tables are not used to compute calibration.

## Open weights and vision

Open weights means the index lists a weights repository or a Hugging Face model repository. Closed models stay on the overall slice.

The vision category fills when an independent vision board is ingested. Text scores stay on the decision category.

## Latency, price, and hosted APIs

The latency slice ranks the lowest same-GPU median milliseconds among models within 5 points of the accuracy leader. Hosted API round-trip stays off that slice.

The price slice ranks the lowest dollars per 1,000 decisions among models within 5 points of the JevBench leader.

The hosted slice ranks JevBench API rows by the headline score.

## Vendor numbers

Vendor decision claims are display-only at weight 0. A vendor-run row, including a maker's own board, does not move a crown.

When the index omits a release date, the first snapshot date is stored as first seen. That date does not start the new-model hold.