This site exists for one reason: the domain name otestujsa.com points at a real and interesting subject — self-testing — and the original project that used the name left almost no recoverable trace. Rather than imitate that project or speak in its voice, this reference documents what is verifiably known about the address and then covers the subject itself in depth.
Everything published here follows two rules. First, claims about the domain are limited to what can be checked in public sources: indexed search snippets, archive records, and third-party measurement tools. Second, claims about learning science are limited to findings that have been replicated and published in peer-reviewed literature. There is nothing to buy, no accounts to create, and no organisation behind the text.