The new ChatGPT is here - what you need to know

We have an AI that finally follows instructions. Here's what that means for your genealogy work.

ChatGPT just released version 5.1. OpenAI marketed it as a personality update to a warmer, more friendly conversation.

And while that is nice, that’s not what matters for genealogy research.

The real change that impacts us is instruction-following. ChatGPT 5.1 understands and follows detailed instructions. For family historians who’ve been frustrated with AI, this is great news.

Here’s what we know about the changes and exactly how to update your prompts and settings.

The core change: improved rule-following

Previous ChatGPT versions mostly ignored our instructions. We’d ask for specific formatting and get something correct once or twice and then watch it drift off.

ChatGPT 5.1 treats prompts as specifications, not suggestions.

This matters for genealogy because our work demands precision. We need transcriptions that mark unreadable text instead of guessing. Research analysis that refers to the records we give it. Family stories that maintain our voice throughout.

This AI now delivers that consistency.

What to change in your ChatGPT settings

Switch to the 5.1 model. As of today, you need to be on a paid plan to see it as an option.

Choose your thinking mode

ChatGPT 5.1 offers two processing options. Find this in the model selector dropdown:

Instant mode handles most genealogy tasks: document transcription, initial story drafts, quick research questions. Use this as your default.

Thinking mode activates extended reasoning for complex problems: conflicting records, impossible timelines, relationship puzzles that need logical analysis. The model shows its thinking process and takes longer to respond.

When to switch to deep thinking:

• Census records that don’t align across decades

• Birth dates that create timeline conflicts

• Family relationships that seem genealogically impossible

• Weighing conflicting evidence from multiple sources

For routine research, stay in fast mode. The quality is excellent.

Delete your custom instructions (for now)

If you personalized your ChatGPT with custom instructions to point out assumptions in thinking, and think longer to solve problems like I did, then it’s time to delete those. Run ChatGPT 5.1 without anything to get a feel for how it works for 10 hours of use first.

You might be pleasantly surprised like I was at the improvements to default mode.

How to rewrite your prompts for 5.1

The old approach: hoping the AI understood what we meant in short phrases.

The new approach: writing even your short prompts as technical specifications.

Document transcription prompts

Before (vague):

“Transcribe this document”

Now (specific):

“Transcribe this probate record. For any word you cannot read with confidence, write [unclear] instead of guessing. Mark names and dates where you’re uncertain with [?uncertain]. Preserve original spelling and abbreviations.”

The specificity pays off. ChatGPT 5.1 follows these instructions, giving us transcriptions that need little error correction on our part.

Research analysis prompts

Before (general):

“What can you tell me about these records?”

Now (structured):

“Review these three census records for John Smith (1900, 1910, 1920). Create a table with: Year | Age | Calculated birth year | Birthplace | Occupation. Below the table, list any inconsistencies in ages, birthplaces, or other details. Suggest which records are most reliable and why.”

This produces organized analysis we can think about and argue with to reach a conclusion.

Family story writing prompts

Before (hopeful):

“Write a story about this ancestor in a way that doesn’t sound like AI wrote it”

Now (detailed):

“Write about Sarah Mitchell’s life from 1890-1950 using this style: conversational narrative as if I’m telling this to family over dinner. Avoid first and second person. Keep paragraphs to 2-3 sentences. When mentioning locations, use ‘town, county, state’ format on first mention, then town only. Include specific dates and details from the records. Avoid emotional language and phrases like ‘one can imagine’ or ‘we can only wonder.’ “

ChatGPT 5.1 maintains that voice for the entire piece. Earlier versions would have shifted styles halfway through.

I enjoy writing long, detailed prompts to get the full power of AI for my work. If you want to try these, check out this post on Thanksgiving research:

Ready to do deeper research on your ancestor's Thanksgiving?

Teach ChatGPT skills

One of the most useful things about AI is having it do repetitive work. It can do that when you teach it the skills behind it, for example:

Create style guides for reuse

ChatGPT 5.1 remembers and applies standards we set. Create a message with your style preferences, then reference it:

“For all my family history writing, follow these standards:

• Citations: Chicago Manual format with repository and call numbers

• Dates: day month year format, no commas (15 June 1920)

• Places: Full format on first mention (Portland, Multnomah County, Oregon), then shorten to city only (Portland)

• Names: Include middle names or initials when known

• Uncertain information: Mark with [possibly] or [source uncertain]

Save this as my writing style guide.”

In future conversations: “Using my writing style guide, write about...” The AI applies those standards consistently.

There’s a few other helpful ways AI can help us and I’ve shared those with my Chronicle Makers community on Skool. I’ll announce a special offer to join for the holidays - stay tuned!

Have ChatGPT teach you and critically think

Genealogy research needs a ton of historical, legal, and social knowledge to do well. Then to apply it requires even more thinking about the records. Here’s how to get AI’s help with both:

Ask for teaching mode

ChatGPT 5.1 can explain history, law, and concepts for any level.

Instead of: “Tell me about probate records”

Try: “Teach me about probate records. I’m comfortable with basic genealogy research but new to court records. Start with what probate records contain, then explain how to interpret them, then show me what to look for in genealogy research.”

The word TEACH triggers educator mode. Instead of dumping facts at you, you’ll get smaller chunks.

Ask for critical analysis

Previous versions accepted everything we told them. ChatGPT 5.1 provides useful critique when we ask.

“I have two conflicting sources for Maria’s birth date. The family Bible says 15 March 1883. Her death certificate says 12 March 1885. Which source is more reliable and why? What additional research would help resolve this?”

The response looks at what professional genealogists call source reliability. AI can explain why timing of record creation matters, and suggest next steps for your research.

This prompt works because we’re prompting for critical thinking which ChatGPT 5.1 is good at.

Get the most out of ChatGPT 5.1

Here’s your check list of how to make the most out of the newest update:

• Write prompts as specifications, not phrases. Be specific about the job to do, what success looks like, and output requirements.

• Create reusable style guides. Teach AI specific styles, then reference them in future conversations for specific output.

• Ask for teaching mode directly. Use the word “teach” to get explanations broken into simple chunks at your level.

• Request critical thinking. ChatGPT 5.1 provides useful analysis when asked to evaluate sources, spot conflicts, and suggest research to do.

You’re still the boss of AI

We all want the highest quality family trees we can build. To get there, we must be the boss of AI:

• Always verify transcriptions against source images. ChatGPT 5.1 is more reliable but not infallible with handwriting.

• Review critical analysis for logic. The AI reasons better now but doesn’t replace our own thinking.

• Check citations and sources. AI can format citations but doesn’t know if a source actually supports the conclusion.

Maintain your research standards. AI assists research. It doesn’t do research for us.

Now tell me, how is it working for you?

How are you adjusting your genealogy work for ChatGPT 5.1?

What tasks are working better for you? Where are you still getting inconsistent results? What prompt templates have been working best for you?

Drop your experience in the comments. Let’s figure out together what works.

Happy Chronicling!

—Denyse

P.S. Not sure where to start? Start with document transcription. It’s the easiest way to see the difference in ChatGPT. Create one really specific transcription prompt, test it on five single page documents, and refine it. Then move to more complex documents.