Tell it what to do when something is missing

Every other check is about what you give the model. This one is about what you have not given it, because something is nearly always missing, such as a date nobody wrote down or an owner nobody named.

A colleague would stop and ask. A model, unless you tell it otherwise, keeps going and fills the gap with the most likely answer. It may write “due Friday” because action items usually have dates, or give the task to whoever spoke last. The result looks complete, and that is what makes it risky: you cannot see which parts were guessed.

This is partly how models are trained. In Why Language Models Hallucinate, researchers at OpenAI and Georgia Tech argue that training and most benchmarks reward a confident guess over an admission of uncertainty. So permission to say “I don’t know” has to come from you. In our study of 319 one-line work requests, not one gave it.

Pick what it should do instead

• Ask first: “If anything you need is missing, ask me before you write.” Best in a live chat, when you are there to answer. See ask it to ask questions first.
• Leave a marked gap: “If a date is missing, write [CHECK] and keep going.” Best for a draft you will review anyway.
• Say so plainly: “If the data does not answer the question, say that it doesn’t.” Best for analysis and questions about documents.
• Assume and list: “If you have to assume something, list your assumptions at the end.” Best when a rough first draft is useful even with gaps.

Turn the meeting notes below into action items, each with an owner and a due date.

Turn the meeting notes below into action items, each with an owner and a due date. If an action has no owner or no date in the notes, write "not stated" instead of guessing, so we can assign it at the next meeting.

The new sentence passes Doubt by giving gaps a visible marker, and saying why passes Purpose too.

Do not make it fill every box

The same habit shows up in structure. Ask for three risks and you will usually get three, even when the project has one real risk. Give it a section called Blockers and something will usually go in it. Say what to do when the honest answer is none: “If nothing is at risk, write Nothing at risk rather than finding something to put there.”

Anthropic’s guide to reducing hallucinations puts permission to say “I don’t know” first among its techniques, and OpenAI’s guidance asks you to say what to do when information is missing. The tell it what to do when unsure pattern has ready-made lines, and for answers you did not ground yourself, the Fact Check List pulls out every number and date to verify.

Use a marker you can search for, such as [CHECK]. Before anything goes out, search the draft for it. A blank you can find is better than a guess you cannot.

Turn my notes from today's kickoff meeting below into a list of action items. I'll send it to everyone who attended. Use a numbered list, one action per line, with what has to happen, who owns it and the due date. No more than 10 items. Leave out the discussion itself, since everyone was there. A good list lets each person find their own tasks in a few seconds. Match the style of this item from last month's list:
1. Book the venue for the spring workshop (owner: events lead, due Feb 2)

If an action has no owner or no date in the notes, write "not stated" in its place rather than guessing, and put those items first so we can assign them.

Notes:
"""
Client wants the launch event in the week of May 12. Events lead to call three venues on the shortlist. Budget cap $40k, client to confirm. Catering: someone to get quotes. Design lead drafts the invitation by April 1. Need a photographer, didn't discuss who.
"""

Write a summary of Q3 sales for our board, who will use it to decide whether to keep funding the online store. Use only the figures below. Under 150 words, as a table with one row per channel, followed by two sentences of commentary. A good summary lets a board member see in one minute whether the online store is growing. Match the format of the Q2 summary:
| Channel | April | May | June | Total |

If a month has no figure, write "not reported" in that cell instead of estimating it, and say in the commentary that the quarter's online total is incomplete.

"""
Shops: July $182,000, August $176,500, September $190,200
Wholesale: July $64,000, August $71,300, September $69,800
Online store: July $38,400, August (no figure), September $45,900
"""

Write answers to the five customer questions below for our help center. Customers read these when they get stuck, so each answer should be under 60 words and start with the direct answer. Use only the release notes for version 4.2, and don't describe features that aren't in them. Follow the same Q&A layout as our existing articles, for example:
Q: Can I export invoices to PDF?
A: Yes. Open the invoice and choose Export, then PDF.

If the notes don't answer a question, write [CHECK with product team] as the answer instead of guessing, so I can fill it in before we publish.

Questions:
1. Can I set up recurring invoices?
2. Do recurring invoices work on the free plan?
3. Can I change the date a recurring invoice goes out?
4. Will my customers get a reminder before a recurring invoice?
5. Can I pause a recurring invoice?

Release notes:
"""
Version 4.2 adds recurring invoices. Choose weekly, monthly or yearly when you create an invoice. You can edit the send date or pause a recurring invoice at any time from the Invoices page. Customers get an email 3 days before each recurring invoice is sent.
"""

Remember. Tell the model what to do when something is missing: ask, mark the gap, or say so. Never leave it free to guess.