# IHEval: instruction hierarchy evaluation (IHEval)

> Tests whether a model follows the priority order of system messages, user messages, conversation history and tool outputs, including when their instructions conflict.

Canonical page: https://benchlm.ai/benchmarks/iheval

- Category: [Instruction Following](/instruction-following)
- Last updated: October 29, 2026

## About IHEval

- Year: 2025
- Tasks: Aligned and conflicting instruction sets
- Format: Conflict-setting accuracy
- Difficulty: Instruction priority
- Paper: [IHEval: Evaluating Language Models on Following the Instruction Hierarchy](https://github.com/ytyz1307zzh/IHEval)

NVIDIA reports it for Nemotron 3.5 Bolt E4B (October 23, 2026), run in its NeMo Gym harness, as accuracy on the conflict setting in reasoning mode.

IHEval is currently displayed on BenchLM for reference, but it is excluded from the weighted scoring formula.

## Leaderboard (2 models)

| Rank | Model | Creator | Score |
|------|-------|---------|-------|
| 1 | [Nemotron 3.5 Bolt E4B BF16](/models/nemotron-3-5-bolt-e4b-bf16) | NVIDIA | 84.79% |
| 2 | [Nemotron 3.5 Bolt E4B](/models/nemotron-3-5-bolt-e4b) | NVIDIA | 82.40% |

## FAQ

### What does IHEval measure?

Tests whether a model follows the priority order of system messages, user messages, conversation history and tool outputs, including when their instructions conflict.

### Which model scores highest on IHEval?

Nemotron 3.5 Bolt E4B BF16 by NVIDIA currently leads with a score of 84.79% on IHEval.

### How many models are evaluated on IHEval?

2 AI models have published results on IHEval in the BenchLM catalog.

### Does IHEval affect BenchLM's overall score?

Not directly. IHEval is still displayed on BenchLM for reference, but it is excluded from the weighted scoring formula.

## Compare Top Models on IHEval

- [Nemotron 3.5 Bolt E4B BF16 vs Nemotron 3.5 Bolt E4B](/compare/nemotron-3-5-bolt-e4b-vs-nemotron-3-5-bolt-e4b-bf16)