Untimed online IQ test · 40 problems · three judgments each
EIDOTHEA: the reconstruction invariance test
In Greek myth, Eidothea, the daughter of Proteus, showed Menelaus how to hold her shape-shifting father fast. Her test asks what must hold while the structure shifts.
Every EIDOTHEA problem gives incomplete evidence about a hidden structure: a ring of glyphs, a set of pairs, nested enclosures, hidden groups. Several structures fit. For each of three claims, decide whether it must hold, cannot hold, or stays unresolved. Work at your own pace, in as many sittings as you need; when you submit, your score and certificate appear at once.
- Untimed
- Three judgments per problem
- Answers saved as you go
- Instant certificate
How it works
Register and pay
Enter your name as it should appear on your certificate, and pay the US$50 fee through PayPal (account or card). Your test is ready the moment the payment completes.
Read each family's guide
What M, C and U mean comes first; then each family opens with its rules, a worked example and the worked answers. Read them first: they are in the test, one click away.
Solve at your own pace
Move freely between the 40 problems and change answers whenever you like. Each answer is saved on the server as you give it; your private link reopens the test on any device, for 90 days.
Submit and get your certificate
Your raw score, IQ on the EIDOTHEA model scale with its interval, a profile by family and a PDF certificate anyone can verify, at once, with a copy by email.
What EIDOTHEA measures
EIDOTHEA measures reasoning under incomplete evidence: keeping in view every structure the evidence allows and deciding what holds in all of them, in none, or only in some. Its four families are ribbon order (a hidden ring of seven glyphs), hidden pairings (four hidden pairs), nested enclosures (a hidden hierarchy) and group echoes (hidden groups seen only through their sizes). Each family opens with its rules and a worked example.
- Family A. Ribbon order
- Family B. Hidden pairings
- Family C. Nested enclosures
- Family D. Group echoes
One attempt per person: each person may take EIDOTHEA once, so every score is a first attempt.
Built to keep outside help out
- Keys on the server. The answer keys never reach your browser, and the result never shows which problems you solved.
- Problems only inside the test. The problem pages are shown only to candidates whose test is open, never on the public site.
- Watermarked pages. Every page is drawn on the screen with a faint watermark of your name and certificate ID.
- Recorded. Leaving the test window, screenshot shortcuts (Print Screen, Windows+Shift+S, Command+Shift+3, 4 or 5), printing (Ctrl+P or Command+P), copy, right-click and drag attempts, paste attempts (pasting is switched off) and AI assistant add-ons in the page are recorded problem by problem, with the server's own times. Printing shows blank pages.
- Checked. The server notes right answers given moments after a long absence from the test, and many problems answered right in a few seconds.
- Sealed and reported. The record is sealed when you submit; its fingerprint is printed on your certificate, so it cannot be changed afterwards. The author's integrity report of your test lists all of it, problem by problem.
No untimed online test can rule out every form of help. These measures make it visible, and the author reviews every result before it counts for a society.
Your result
Scored with the provisional model norms EM0.2 of EIDOTHEA (model-based; no norming sample yet). Deviation IQ, mean 100, SD 15. No percentile is reported: no norming sample has been tested yet, so a score is a position on the test's own scale.
Societies. IQ 147 or higher meets the criterion of the Nereid Society, IQ 160 that of the Mesopelagic Society (with a one-time membership fee), and IQ 190 that of the Aphotic Society. Just below the criteria, IQ 135 to 146 qualifies for associate membership of the Nereid Society and IQ 180 to 189 for subscription to the Aphotic Society, each with a one-time admission fee. The criteria of the Hadal and Exocosm Societies lie above EIDOTHEA's scale, which ends at IQ 202.
Take EIDOTHEA online
A computer or tablet is best: the problem pages are detailed, and a larger screen shows them whole. A phone works too (zoom in on the page). Keep scratch paper ready.
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Please check back soon, or take THETIS, the adaptive online test, today.
Your details
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Payment
- EIDOTHEA online: untimed test, scoring and certificateUS$50
- Name on certificate
PayPal processes the payment; you can pay with a PayPal account or a debit or credit card. Your test is ready the moment the payment completes, and you can begin at once or later.
Have a code?
Your test is ready,
- Untimed. Once you begin, your test stays open for 90 days. Work in as many sittings as you like; your private link reopens it on any device.
- Start with what M, C and U mean, and each family's guide: they explain the notation. Then answer the 40 problems in any order, and change answers as often as you like before you submit.
- A problem scores one point only when all three judgments are right. No marks are taken off for wrong answers, so answer every problem.
- Answers are saved on the server as you give them. Nothing tells you whether an answer is right, and the result never shows which problems you solved.
- Work alone, with scratch paper only. Leaving the test window, screenshot shortcuts, printing, and copy or paste attempts are recorded with your result for the author's review.
Camera check (required)
While a problem is on screen, this page watches your camera for a phone, another person or an empty seat. The check runs in your own browser: the video never leaves your device. When it sees one of these, it keeps a small still picture for the author's review, deleted after 90 days. It never changes your score, and your certificate's verification page shows that it covered your whole test.
- Sit facing the camera in good light, with your face in view.
- Keep your phone and other devices out of reach, and work alone.
- If the camera stops, the problem is covered until it is back. Breaks are fine: close the page or step away between problems.
Your answer
Submit your answers for scoring?
Your EIDOTHEA result
- Raw score
- 90% interval
- By family
Your certificate
Certificate ID . Anyone can check it at .
Record fingerprint : the server sealed your answers and what this page recorded when you submitted. The same fingerprint is on your certificate, so the record can never be changed without the change showing.
Next: take THETIS (adaptive) or RUFIT (timed) for a second, independent measure, or read about the five societies.
EIDOTHEA: questions
What is EIDOTHEA?
An untimed online test of fluid reasoning, from the EIDOTHEA research edition E0.1.0 (form E-A): 40 problems in four families of ten (ribbon order, hidden pairings, nested enclosures and group echoes). Each problem shows incomplete evidence about a hidden structure, and several complete structures fit it. You judge three claims: M if a claim holds in every structure that fits, C if it holds in none, U if it holds in some and not in others. A problem scores its point only when all three judgments are right. Every answer was proven by an exhaustive computer check of every possible structure.
How long do I have, and can I take breaks?
EIDOTHEA is untimed. From the moment you begin, your test stays open for 90 days: work in as many sittings as you like, on any device, with your private link. Every answer is saved on the server as you give it. When you are done, submit: your result and certificate appear at once. A test still open after 90 days is submitted with the answers saved by then.
What does the fee cover?
The US$50 fee, paid once through PayPal before the test opens, covers the online test, its scoring, your result with its PDF certificate, and the review of one society application. Admission as a full member of a society carries no further fee.
Can I take it more than once?
How precise is an EIDOTHEA score?
EIDOTHEA is a research edition. Its provisional model norms EM0.2 place raw scores 0 to 40 between IQ 81 and 202 (SD 15), using a model whose item difficulties are assumed: no norming sample has been tested yet, so a score is a provisional position on the EIDOTHEA scale, not a percentile of the population, and no percentile is reported. The model error is about 4.5 IQ points from about IQ 120 to 160, and larger toward the ends of the scale. The end points, IQ 81 and 202, are conventions of the model, not measured values. The norms will be replaced by empirical norms as results come in.
How does the online test keep AI and other help out?
The answer keys never leave the server, and your result never shows which problems you solved. The problem pages are shown only to candidates whose test is open, and each is drawn on the screen with a faint watermark of your name and certificate ID. While a problem is on screen, the test page records leaving the test window, screenshot shortcuts, copy, print and drag attempts, attempts to paste into the answer fields (pasting is switched off), and AI assistant add-ons that insert themselves into the page; the server keeps its own times, and notes right answers given moments after a long absence. The record is sealed when you submit, and its fingerprint is printed on your certificate. None of this changes a score: the author reviews it before any society admission. An untimed test cannot rule out every form of help, which is why you declare that you will work alone, and why the author reviews every result before it counts for a society.
What if I lose my link or change devices?
Your private link (shown when your test is ready, and kept in this browser) reopens your test on any device. If you lose it, use “Recover my test” with the PayPal Transaction ID from your receipt and the email you registered with. Answers that are complete are saved on the server; a part you have only begun is kept in the browser you were using until you complete it.
Rules, fee and privacy
Test rules
Work on EIDOTHEA alone, with scratch paper only: no person, AI system, search engine, calculator, program, published solution or other aid. Do not copy, photograph, record or share the problems or your answers. Each person may take EIDOTHEA once, and a test belongs to the person registered for it. You may take as many breaks as you like within the 90 days. Results that show signs of outside help may be withheld from society admission or withdrawn.
Fee and refunds
The fee is US$50, paid through PayPal (PayPal account or card) before the test opens. It covers the online administration, scoring, your result and certificate, and the review of one society application. Because the problems are shown as soon as a test begins, a test that has begun cannot be refunded. If a payment went through but the test did not open, use “Recover my test”, or write to jresquites@mensaphilippines.org with your PayPal Transaction ID.
Privacy notice
Your name, email, year of birth, country and earlier scores are used to run your test, to issue and verify your certificate, to build the norms and, with your consent, in de-identified research summaries. Your answers, the times the server kept and the integrity record (departures from the test window, screenshot shortcuts, copy, paste or print attempts, and the names of AI assistant add-ons found in the page; other add-ons are never recorded) are kept with your result for scoring, norm updates and the review of society applications. The camera check, which every test requires, runs in your own browser: the video from your camera is analyzed on your device and is never sent or stored. When it sees a phone, another person or an empty seat while a problem is on screen, the page sends one small still picture (160 by 120 pixels) with its time, kept for the author's review and deleted 90 days after it was taken; its summary of each problem (how long it watched, and when it saw any of these) is kept with your integrity record. The detector's program and model load from public servers (jsDelivr and Google), which see your device's address as any website does. How you reached the site (the name of the site or app that linked to it, or the tag in the link you followed, which your browser keeps for 30 days) is recorded with your payment, without your name, to count which channels bring candidates. When your test ends, your result, the private link to it and the link to your certificate are emailed to you (through Resend, an email service). Your email is never shown publicly, and you can hide your name on the public verification page at any time. Data are stored by Netlify and Redis Cloud and are never sold.