Disagreement as a prompt
- What I took from it
- The model can already argue back. What's missing is a default, a structure and a memory of where the argument has got to.
Self-initiated concept · Web · AI · Designed and built · 2026
Parallax is a live web app that tests your opinions instead. Type what you think, and it asks one question at a time, makes the strongest case against you, and shows where your argument holds.
Every AI assistant is good at telling you that you're right. I wanted to design one that helps you find out.
Parallax starts with one sentence, typed the way you'd say it to a friend. It doesn't answer with an essay or argue back. It asks what you mean, then what you're assuming, looks for evidence, makes the strongest case against you, and asks what changed. Beside the conversation, a map of your argument fills in, and “Where do I stand?” gives a plain audit at any point.
Parallax is the way an object shifts when you see it from two positions. A belief works the same way: you can't judge it from one place. I designed it, built the front end, and put it online at parallaxproject.co.
Result: against a chatbot told to argue with them, 6 of 8 people could name the weakest part of their own argument with Parallax, up from 2 of 8.
How much more often 11 leading AI models affirmed a user's actions than people did, including when the user described deceiving someone.
Cheng et al., 2025Between OpenAI shipping a GPT-4o update that made ChatGPT more flattering and starting to roll it back.
OpenAI, 2025Knowledge workers surveyed. The more they trusted the AI, the less critical thinking they reported.
Lee et al., CHI 2025Students who wrote an essay with ChatGPT and couldn't quote a sentence of it minutes later. Without it, about 11%.
Kosmyna et al., 2025 (preprint)Chat assistants agree with people too much. Researchers call it sycophancy: a model shifts toward whatever the user seems to believe, and drops a correct answer when pushed (Sharma et al., 2023). OpenAI's own explanation of its 2025 rollback was that the update leaned too hard on the thumbs-up people give when they hear what they want.
The incentive runs the wrong way. In the Cheng study, people who talked to a flattering model rated it higher, trusted it more and wanted to use it again. Yet people find holes in someone else's argument far more easily than in their own (Mercier & Sperber, 2011), and asking them to consider the opposite reliably corrects biased judgment (Lord, Lepper & Preston, 1984). The most useful thing a conversation partner can do is disagree with you well, and that's what assistants are tuned away from.

How might I make having your opinion challenged feel like something an AI does for you, not to you?
When people use a chatbot to think through an opinion, what do they want from it, and what do they do with its pushback?
| Study plan | |
|---|---|
| Hypothesis | People want their views tested, but a chatbot's pushback is too long and too short-lived to show them where they're weak. |
| Objective | Learn when people want agreement or a challenge, what they do after it, and what makes a challenge feel fair. |
| Generative method | 6 semi-structured interviews, a 1-week diary study of every time each person used a chatbot on an opinion, and an interview with a debate coach. |
| Evaluative method | Within-subjects test, n = 8: a chatbot told “argue against me” against Parallax, order counterbalanced. Then a second round of 5 after fixes. |
| Participants | Weekly chatbot users aged 23–52, including a dyslexic participant who dictates, a blind screen reader user and a phone-only night-shift nurse. |
| Non-objectives | Changing anyone's mind. Holding a view is a valid result. |
Alongside the papers above, I took apart four products that already make disagreement useful.
I wrote one observation per sticky, one colour per person, sorted them by hand into findings, then ran a cluster pass over the sort.



In the readout, the debate coach pushed back on my plan to open with the counterargument: “Never open with the counter. Make them say what they mean first.” That moved it to stage four.

People about to argue, publish or act on a view, who would rather hear the objection now. I left out people looking for facts, who need an answer engine, and people who want ammunition to win against someone else.
Job to be done: “Before I commit to this view, show me where it's weak, without making me feel stupid for holding it.”
The outcome is a belief you understand better. Whether you keep it is up to you.

Three pages. The landing input starts the conversation. The debate page holds the conversation and an analysis panel with Reasoning, Argument map and Reflection views. A public design system page documents the rest. No account, history or settings, so the only thing to evaluate is the conversation.
| Stage | The question it asks | Why it's in this position |
|---|---|---|
| Clarify | What do you mean? | Most disagreements are about definitions. |
| Assumptions | What are you assuming? | The weak point is usually unstated. |
| Evidence | What supports it? | Separates what's known from what's felt, with sources. |
| Counterargument | The strongest opposing case | By now it can aim at what you actually believe. |
| Reflection | What changed? | Hands the conclusion back to you. |

The product never says whether you're right. It can call a claim supported, weak or contradicted. Value judgments get their own label instead of a grade. Dropped claims stay visible, struck through. The audit ends on “What would change the picture”, not a verdict.



| Avoided | Used instead | Why |
|---|---|---|
| Start debate | Challenge my thinking | The person asks for the challenge |
| You're wrong | Weak link | Names the part, not the person |
| Rebuttal | The strongest opposing case | A case to consider, not a blow |
| Final score | Where do I stand? | The person's own question |
| No results | Searched, nothing reliable found | Admits the limit |
Three features turn a chat into an examination: a fixed order of questions, a map of the argument, and an audit you can ask for at any point.
Parallax doesn't answer with an essay. It asks what you mean, what you're assuming and what supports it, then makes the strongest case against you and asks what changed. Each reply ends on one question, with its sources underneath.
Beside the conversation, every claim, definition, assumption and counter becomes a node with a status. Dropped claims stay on the map, struck through, so nothing quietly disappears.

One tap gives an audit: your position quoted back to you, what holds up, the weak link, your assumption, and what would change the picture. The product never says whether you're right.

I built in code from the start. I was designing the behaviour of a conversation, and a mockup can't show whether a question lands.
| Layer | What I used | Why |
|---|---|---|
| Interface | React, three routes | Conversation, stage and panel are views of one state |
| Styling | Design tokens as CSS variables | One source for colour and type, shown on the system page |
| Motion | Spring-based layout animation | Controls, replies and map nodes all move the same way |
| Conversation | One endpoint returning a structured reply | See below |
Each turn returns the message, the current stage, the checks run, the map nodes with types and statuses, sources and, when asked, the audit. The stepper, map and conversation never disagree because they're drawn from the same reply. The audit is its own intent, so the same question always gets the same shape of answer.
I ran a within-subjects test with 8 weekly chatbot users, none from the interviews. Each brought an opinion and took it through a general chatbot told “argue against me” and through Parallax; half started with each. They did four tasks per version. I measured unaided completion and ease per task (SEQ, 1–7). The key check was whether they could name the weakest part of their own argument. The debate coach also scored each final position, blind to version, on a 1–5 reasoning rubric: 2.6 with the chatbot, 3.6 with Parallax.

| Task | Chatbot | Parallax | What I saw |
|---|---|---|---|
| Get the strongest case against your view | 8 / 8 | 7 / 8 | The chatbot is faster here. One person left Parallax during Clarify. |
| Name the weakest part of your own argument | 2 / 8 | 6 / 8 | Most read it straight off the map's weak node. |
| Say which source backs which claim | 3 / 8 | 7 / 8 | Chatbot sources sat at the end, unlinked to claims. |
| Get a summary of where you stand | 4 / 8 | 7 / 8 | The chatbot restated the view in nicer words. One person missed the audit button. |
Still open: one participant's ease stayed at 4; they wanted the answer faster, and Parallax is slower by design. Only 3 of 8 opened a source. And people still said the chatbot felt nicer, though 6 of 8 chose Parallax for a real decision coming up.
That last result is the measurement trap from section 02. So the north star is examined beliefs: conversations that reach Reflection or an audit. Guardrails are drop-off after the counterargument, sources that don't support their claim, and the rate of changed minds. If nearly everyone changes their view, the product is persuading, not examining.