# Quarterly research with source checks

An Anthropic research evaluation checks reported figures and quotations against an offline web corpus.

Canonical URL: https://aiidelist.com/blog/opus-5-5-quarterly-research

Language: en

Published: 2026-09-25

Updated: 2026-09-25

An Anthropic research evaluation checks reported figures and quotations against an offline web corpus.

## What the source shows

Anthropic reports that 16 of 18 Opus 5.5 attempts passed a strict factual check in a quarterly-performance research task. The evaluation used a web copy in which the relevant earnings release was difficult to locate.

## What to inspect

The reported pass rate applies to this test and its grader. It should not be generalized to every research task. Inspect source retrieval, date alignment, arithmetic and citation support separately; a polished report can still contain unsupported claims.

## A useful way to try this

Build a small source pack for a company and quarter you can verify. Require a citation for each numeric claim and preserve the exact source text used by the model. Review incorrect and omitted facts as well as the final narrative.

## Evidence and limitations

This is a vendor-published report, not an AI IDE List benchmark. The underlying environment and complete execution transcript are not available in this listing. The evidence panel above records the source type, settings and prompt attribution. AI IDE List has not independently reproduced this result.

[Open the source](https://www.anthropic.com/claude-opus-5-5).

[Explore Claude Opus 5.5 examples](/models/claude-opus-5-5/examples) or [compare model specifications and costs](/models/compare/claude-opus-5-5-vs-gpt-6-astra).