BuildSpark AI
Lesson 1 of 8Jump to Try it

Home · Start here · Lesson 1 of 8

See how an AI tool writes its answers, and what it can see

Know when an answer is a guess, so you check the right parts.

Lesson 1 of 8 · about 4–5 min reading + 5 min doing · last checked 2026-10-19

Recall

Recall: Think of a time an AI tool sounded sure and was wrong. Was it a name, a number or a date? Keep that example in mind as you read.

The idea

An AI tool runs on a language model: a program trained on large amounts of text to predict what comes next.

It writes a reply one likely word at a time. It draws on three things: what it learned in training, what's in your chat, and anything it's connected to, such as search or your files. A fact that comes from none of these is a guess that reads like a fact.

What a reply is made fromThree inputs, Training text up to a cutoff, Your chat typed or attached, and Connections such as search or files only if on, point into a box labelled Language model, writes the likeliest next word. That box points to Reply. Two bubbles show 2014 and 2016.Training textup to a cutoffYour chattyped or attachedConnectionssearch, files, if onLanguage modellikeliest next wordReply20142016
Same question, different answer: a sign to check.

How it works

One likely word at a time

OpenAI's help page says the model predicts "the next most likely word when generating a response, one word at a time." It doesn't look up a stored answer. It builds a new one each time, from patterns in the text it learned from.

Prediction can be right or wrong

NIST, the US standards agency, says language models "predict the next token or word in a sentence or phrase." A token is a small piece of text, often a word or part of one. NIST adds that such prediction "can produce factually accurate and consistent outputs," but "it can also produce outputs that are factually inaccurate or internally inconsistent."

Same question, different answer

OpenAI explains there is "an inherent element of randomness in how the model responds. As a result, the same question may yield different answers across different queries." That's useful to you. Ask twice, and the parts that change are the parts to check.

Training stops at a cutoff

Each model learns from text up to a date, called its knowledge cutoff. Claude's help says models "may not be aware of events or information that occurred after their respective cutoff dates." Ask about last month's news without search, and you may get an older answer that sounds current.

Search and files add what training lacks

With search on, a tool can bring in current pages. Claude's help says every search response includes citations. OpenAI says search responses "may include citations." If you attach a file, the tool can read it. If you didn't attach it, it can't quote it.

A confident tone isn't evidence

NIST describes tools that "generate and confidently present erroneous or false content in response to prompts." Its name for this is "confabulation." The wording sounds just as sure when the fact is wrong.

EXAMPLE · the company and both years are inventedSee how one confident founding year turns out to be a guess.

Before

You ask, "What year did Northwind Kitchens open its Oslo shop?" The tool answers "2014" in a confident sentence. You paste it into a client email.

After

You look at what the tool had to go on. There's no search indicator and no link, and you gave it no document. Only training could supply the year, and for a small company that's a guess. You ask again in a new chat and get "2016". Two answers mean neither is checked. You turn search on and open the cited page, or you ask the company.

Practice

Step 1 (done for you): The reply gives a founding year. You attached nothing, and you gave no year.Step 2: Did it search and show a link? No. So where did the year come from?

Is this part a guess?

Ask these about one fact in the reply.

Ask about one fact If yes If no
Is it in something you gave it? Compare it to that text (Lesson 4) Ask the next question
Did it search, and show a link you can open? Open the link and find the fact (Lesson 4) Ask the next question
Is it recent, niche, or a precise number, name or date? Treat it as a guess and check it (Lesson 4) Lower risk. Still read it.

Try it in your own AI tool (3 min)

Ask the same factual question in two new chats. Pick something you can check, such as a detail on your company's public "About" page. Mark what changed between the two replies. Then check one detail against a page you trust.

Show the model answerCompare your two runs with ours, and spot the detail that was guessed.

"Run 1: 'founded 1998, 40 staff'. Run 2: 'founded 1998, about 50 staff'. The year matched, and the About page confirms it. The staff numbers differed, and the page gives none. So the staff figure was a guess, and I won't use it."

Check

Question 1 of 4. You ask about a rule your city changed last month. The tool shows no search and no links, and the answer sounds sure. What is the answer most likely based on?

Question 2 of 4. A colleague asked your exact question in the same tool today and got a different answer. What's the most likely reason?

Question 3 of 4. You attach a spreadsheet and ask, "Is the total right?" The upload failed, but you didn't notice. The reply says, "Yes, the total of €48,200 is correct." What happened?

Question 4 of 4. A colleague says, "It knows our company, because it named our CEO." Which explanation fits best?

SourcesOpen the 5 source pages behind this lesson's claims, all checked 2026-10-19.