Skip to content

IntermediateLesson 4 of 58 min read

Extracting data from a stack of documents

A course from the Academy: Working on your documents

Go to the quiz ↓

Thirty invoices, fifty job applications, a hundred free-text responses to a questionnaire. Turning that into a table is the most spectacular time-saver an AI can offer.

Define the columns BEFORE

The mistake is saying "extract the important information". Each document will then produce different columns and nothing will be comparable.

"For each invoice, extract exactly these columns: supplier, number, date, amount excluding tax, VAT, amount including tax. If any information is missing, write ABSENT and invent nothing."

The "ABSENT" is essential: without an explicit instruction, a missing field will be filled with a plausible value, and you will never know which one is real.

Process in batches

Five to ten documents at a time. Beyond that, quality drops and you can no longer reasonably verify. You will assemble the batches afterwards.

Spot-checking

Don't check everything, that would be as time-consuming as doing it by hand. Pick three rows at random and verify them in full against the original document. If all three are correct, the batch is probably fine. If one is wrong, redo the whole batch: errors rarely come alone, they stem from a misunderstood format.

Watch out for personal data

Fifty job applications means fifty people. On a consumer-grade service, that is exactly the case you should not process without a contracted professional version.

Do this now

Take five documents of the same type. Define your columns, request the extraction with the ABSENT instruction, then check two rows at random.

Complete the lesson

A 4-question quiz: 3 correct answers are enough, plus an exercise to practise. It opens in the Academy, on this same lesson.

Take the quiz and complete the lesson Free. With an account, your progress is saved and leads to the course certificate.

The course: Working on your documents

  1. A long document: better to split it up than to hand it all over at once.9 min
  2. Tables and figures: a minefield9 min
  3. Compare two versions of the same document.8 min
  4. Extracting data from a stack of documents8 min
  5. Building reusable prompts7 min

The whole Academy →The AI glossary