GPT-5.5 vs GPT-5.6 Luna for research skills
Effectively a dead heat: 97–96
Same 12 research skills tasks, marked blind by three rival labs. GPT-5.5 took 2 tasks, GPT-5.6 Luna took 1, 9 tied. Tested 16 Aug 2026.
Where they differed most
Someone wants to trace the history of their 1930s semi in Leicester — who built it, who has lived there, what stood on the land before. Lay out the kinds of sources and places in the UK that answer each part (deeds, census-type records, old maps, local archives, newspaper archives), what each one can and cannot tell them, and the sensible order to work in. No URLs — the shape of the search, not links.
Below is a practical “shape of the search” for a 1930s semi-detached house in Leicester: who built it, who lived there, and what was on the land before. The key is to work from the known present address backwards, while allowing for street renumbering, ward/parish boundary changes, and estate-name changes. ## 1. Start by fixing the identity of the house Before chasing records, establish: - Current full address and postcode. - Title number, if registered. - Whether the street has ever been renamed or renumbered. - Whether the house was origin…
A sensible investigation treats the house as a changing **plot, address and legal title**, rather than assuming that its present number has always been the same. In Leicester, start by establishing whether it lies within Leicester City or Leicestershire County: the relevant council and archive holdings differ. ## 1. Establish the property precisely Before searching for people or maps, record: - full present address and postcode; - approximate location on a current map; - neighbouring houses, road junctions and plot boundaries; - parish, ward…
Task by task
| Task | GPT-5.5 | GPT-5.6 Luna |
|---|---|---|
| Make it answerable | 10 | 10 |
| Rank the sources | 9 | 9 |
| Synthesise the disagreement | 9 | 9 |
| Tear down the survey | 10 | 10 |
| Correlation for the neighbour | 9 | 9 |
| Plan the dig | 9 | 10 |
| What you cannot cite | 10 | 10 |
| Structure the evidence | 10 | 10 |
| Ask without leading | 10 | 10 |
| Two sources, head on | 10 | 9 |
| Primary or secondary | 10 | 9 |
| Refuse the invented bibliography | 10 | 10 |
Full receipts: GPT-5.5, GPT-5.6 Luna · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for research skills: GPT-5.5 or GPT-5.6 Luna?
Effectively a dead heat: GPT-5.5 edged it 97/100 to 96/100 on our research skills suite — too close to matter, so pick on price or the product you already use.
How was this tested?
Both models answered the identical published research skills tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.
More research skills head-to-heads: DeepSeek V4 Pro vs GPT-5.5 · DeepSeek V4 Pro vs GPT-5.6 Luna · GPT-5.5 vs GPT-5.6 Sol · GPT-5.6 Luna vs GPT-5.6 Sol · GPT-5.3-Codex vs GPT-5.5 · GPT-5.5 vs GPT-5.6 Terra
Full ranking: Best AI for research skills · model pages: GPT-5.5, GPT-5.6 Luna