How we differ from population-simulation vendors.
A category of AI vendors now sells large-scale "simulation of people" to enterprises and governments: striking claims, gated demos, no published method. This page compares approaches, not companies — on the axes any serious buyer should test every vendor against, including us.
What actually separates the two approaches
In one sentence: a gated simulation vendor asks you to trust a result you cannot inspect, while LEXUN publishes the method, shows the error bars, keeps a public calibration record and hands you a way to reproduce the answer yourself. The nine rows below are the axes where that difference stops being rhetoric and becomes something you can test — each one is a question you can put to any vendor, including this one, and expect an artefact in reply rather than an assurance.
| Axis | Typical gated simulation vendor | LEXUN |
|---|---|---|
| Published method | Undisclosed; "proprietary simulation" | Full methodology public on the Accuracy Centre; model maths documented per domain in the method guides |
| Error bars | Point claims ("we predicted X within 0.n%") | Every probability shown as a band; binomial standard error disclosed; false precision refused by design |
| Calibration record | None published | Public Brier-scored record, computed only from resolved outcomes — published from an honest zero on day one, growing only as reality answers |
| Reproducibility | Not offered | Seeded and versioned: identical inputs reproduce identical outputs — verify in your browser now |
| Tamper evidence | Not offered | Every result is sealed with a SHA-256 hash over its canonical bytes and the audit record is hash-chained — check a result without trusting us |
| Stated moat | Scale, data access, proprietary method | Scoring, receipts and elapsed time — set out in full, including what is not a moat, on the defensibility page |
| Access | Demo request, sales-gated | Free and in your browser today — no Key needed to run a decision; a LEXUN Key is required to save one, and a Key is a free passcode that encrypts your record on your own device rather than an account on ours |
| Refusal behaviour | An answer for everything | "Insufficient evidence" is a real output; out-of-scope domains are declined, not improvised |
| Data handling | Your scenario data on their servers | Local-first: simulation inputs and saved decisions stay in your browser; the optional Copilot sends only what you type into it and a filtered result summary — architecture, plainly |
The questions to ask any simulation vendor
- Can I see the calibration record, and who computed it?
- What does a forecast look like when you are uncertain?
- Can I re-run yesterday's prediction and get the same answer?
- What happens when I ask something outside the model's competence?
- Where does my data live while you simulate with it?
We publish our answers. Demand everyone's.
What we refuse to fake — and why that wins
A comparison that only flatters its author is marketing, so here is our position, plainly — every line of it a choice, not a gap. Our public calibration record started from zero on day one, and the Accuracy Centre printed that zero in the open: that is what an honest record looks like at the start, and it is exactly why it will be unanswerable later — a record that started earlier can be caught up with; one that started honest cannot be faked. We have not found a published, scored forecast record among the vendors we reviewed; if one exists, we will link to it here. Our coverage is three decision domains — business runway, career change, major purchase — built deep rather than a catalogue built thin: versioned models, stated weaknesses, reproducible to the byte. And when a question sits outside them, the engine says so instead of improvising — the refusal is the feature. An engine that answers everything is an engine whose answers mean nothing.
Which approach fits which buyer
Gated population simulation is built for organisations buying scale: large panels, bespoke modelling engagements and a supplier relationship with account managers attached. LEXUN is built for the person or small team facing one consequential decision this week whose reasoning has to survive scrutiny afterwards — from a board, an auditor, a co-founder, or their own future self reading it back in a year. The two are not really chasing the same budget. They are chasing the same claim: that a number on a screen has earned the right to be believed.