Comparison
Lumi or ChatGPT for revision?
We make Lumi, so weigh this accordingly. We have tried to describe ChatGPT as its own users would, because a comparison that misrepresents the other side is no use to the person reading it.
The short answer
They are good at different jobs. ChatGPT is a general assistant: ask it anything and it will answer, across every subject, better than any narrow tool could. Lumi is a tutor: it is trying to get one idea into one person’s head, and it is built around the moment where that is not happening.
If you can already follow your lessons and you want something that answers questions quickly, a general assistant is probably enough. If you have read the same page three times and it will not go in, you do not need another answer — you need somebody to work out which step you lost.
What ChatGPT is better at
Worth saying first, because it is a longer list than a page like this usually admits.
- Breadth. It knows about everything, including all the things that are not on any syllabus.
- Writing and code. It is better at both than any tutoring product, ours included.
- Research and summarising. Give it a long document and ask what it says.
- Price. Its free tier does more than Lumi's free plan does.
- Being one tool. There is real value in not having six tabs open, and every extra app is a thing you have to remember to open.
Where a tutor is a different thing
None of these are about the underlying model being better. They are about what the product is built to do with it.
It works out where you got lost
A general assistant answers the question you asked. That sounds like a feature and often is, but the question a stuck student asks is rarely the question they need answered — it is a symptom of a gap two steps earlier. Lumi works back to that step and starts there. You can get a chatbot to do this by telling it to every time; almost nobody does, at eleven at night, in week nine.
It draws while it talks
Most of what is hard about A-Level maths, physics and chemistry is spatial or procedural. A prose description of a force diagram is a worse force diagram. Lumi builds the thing on a whiteboard as it explains, so you watch the working appear in order, and you can point at a part of it and ask what that bit is doing.
It changes the explanation
Tell it that did not land and you get a genuinely different route in — an analogy, a worked example, a diagram, a different starting point — rather than the same explanation restated at greater length.
It reads your working
Photograph your attempt or draw it on the pad and Lumi reads the handwriting — what is right, what is wrong, and the exact line it went wrong on. A chatbot sees a question; a tutor sees your attempt at it. It also sets and marks homework, so the checking is not left to you.
It knows which exam you are sitting
Tell it your board and it teaches to it, including which formulae are given to you in the exam and which you are expected to recall. Boards differ on that, and revising the wrong side of the line costs marks. The courses checked line by line against the specification are eight AQA and Edexcel qualifications, 471 objectives — the part of the coverage that is verified rather than claimed.
It hands you an explanation, not an essay
This one is a deliberate limitation rather than a capability. A tool that will write your coursework is a tool that will eventually cost you a qualification, and the essay you did not write is the topic you cannot answer on in June.
How to actually use both
- Stuck on a topic, not a question: a tutor. Something has not landed and no amount of answers will find it.
- Need a fact, a value or a definition checked: whichever is already open.
- Writing an essay: write it yourself, then ask either one for feedback on what you wrote. Ask for feedback, not for a rewrite.
- Practising: a past paper under time, marked against the mark scheme. Neither tool replaces this and neither pretends to.
- Anything that decides a mark: check it against your specification. Both can be confidently wrong.
Common questions
Yes, and plenty of students do, productively. It explains well, it is available, and the free tier is generous. What it will not do unprompted is find out what you already understand before it starts, show you a diagram being built, notice you have gone quiet on a step, or hold you to your exam board's specification. You can get some of that by prompting carefully every time. Most people do not.
It teaches rather than answers: it talks back and draws the working on a board as it speaks, so you watch the explanation appear rather than reading a finished answer. It changes the explanation when you say it has not landed, teaches from a past paper, photo or YouTube link you attach, reads handwritten working line by line, sets and marks homework, and remembers how you learn between lessons. Reviewed teaching packs cover eight AQA and Edexcel courses. It is also built to hand you an explanation rather than a finished piece of work.
At a lot. It is far broader, it writes and codes better, it handles research and general knowledge across every subject on earth, and it is free at a level Lumi's free plan is not. If you want one tool for everything, it is the better tool. Lumi is narrower on purpose.
For working through a problem where you have lost the thread, a tutor that draws the steps and stops to check you are still with it. For a quick check of a value or a definition, whichever is already open. The honest split is that a general assistant is better at answering and a tutor is better at teaching.
Not for revision — revision is not assessed. It becomes cheating when work you did not write is submitted under your name, which makes coursework and non-exam assessment the place to be careful. That is true of both tools and of a human tutor who writes your essay.
No, and most students should not. They cost different amounts and do different jobs. Use a general assistant for breadth and a tutor for the topic that will not go in.
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