Module 1 · Lesson 5 of 6 · with Nova

Why AI Sometimes Gets Things Wrong

Objective

Understand how AI can produce convincing but inaccurate information, distinguish common error types and apply proportionate checks to important claims.

An AI assistant can explain something complicated so smoothly that the explanation feels settled. That's one of its strengths — and one reason you need to understand what a convincing answer does, and doesn't, tell you.

Suppose you're comparing two energy tariffs and ask an assistant to explain a complicated price change. It gives a confident summary, complete with figures and a neat conclusion. The language is easy to follow, so the temptation is to assume the numbers must have been checked. But producing a convincing explanation and establishing a verified fact are different tasks.

A language model learns patterns of language and information during training. When it generates an answer, it isn't automatically looking up every claim in an authoritative source. Some assistants can search or use documents, but unless those capabilities are actually used, a response may rely on learned information that is incomplete, outdated or mixed together incorrectly. An invented quotation, plausible-looking citation or mistaken date can appear alongside perfectly sensible explanations.

Let's imagine the assistant says a household tariff will increase by eighteen per cent. You ask where that number came from and discover it refers to a different region and an earlier pricing period. The model may have combined individually plausible details into a conclusion that doesn't describe your situation. The important failure isn't just a wrong number. It's a failure to connect the right evidence to the particular question being answered.

This is sometimes called a *hallucination*, although that informal term can conceal several different problems. An answer may fabricate an entire detail, misinterpret a genuine source, apply a true general rule to the wrong situation or state an uncertain claim too confidently. Those errors call for different responses. Better phrasing alone won't supply information the assistant doesn't have; current sources may solve a missing-data problem, while a different method may be needed for exact arithmetic.

How cautious should you be? It depends on the task. If you're asking for names for a fictional café, you don't need to audit every suggestion. If you're choosing an electricity tariff, planning travel around opening hours or interpreting something that affects your health or finances, the details matter. Checking those facts against the relevant original information is part of completing the task, not evidence that AI is too risky to use.

AI can still help you do a great deal of the preparation. It might identify the factors you should compare, explain technical terms, organise a list of questions or suggest a sensible way to calculate total cost. It can help you understand the evidence once you've found it. What it shouldn't do is replace the evidence with confidence.

The habit to develop is *proportionate verification*. Enjoy the creative and explanatory benefits of AI, then match your checking to the importance of the decision and the nature of the claim. You'll become more capable by understanding the limits, not by treating every useful response as a trap.

Let's take the tariff example a little further. Imagine two providers advertise rates in different ways. One page emphasises the unit price, another highlights the standing charge, and an older comparison article presents an annual estimate. An assistant could combine those figures into a tidy table. But if it treats an old estimate as a current quote or compares different regions, the table may look authoritative while the comparison is fundamentally unfair.

That doesn't mean the comparison is beyond AI's reach. You could ask it to explain the components of an energy bill first: the unit rate, standing charge and expected usage. Once you understand those parts, you can provide current figures from the providers and ask for help organising them. If the assistant has a calculation tool, it may also help work out illustrative totals. You still need to make sure the inputs describe the same circumstances before treating the result as meaningful.

The kind of answer you're seeking should determine the method. If you're asking why a tariff includes a standing charge, an explanation may be exactly what you need. If you're asking for today's cheapest available tariff for your household, you need current, relevant information. If you're asking for the total cost under several usage assumptions, you need a calculation based on consistent numbers. These tasks sound related, but they require different kinds of support.

It's useful to recognise that uncertainty can be a productive answer. If an assistant says it cannot establish current prices without searching, that may be more valuable than an invented bargain. You can then decide whether to supply the information, use a search-capable tool or narrow the question. Fluency includes knowing when to change the method rather than simply asking the same question more forcefully.