From W3C Wiki

When designing a specification with testability or not, it may be hard to evaluate whether a given assertion is testable or not; testability is often confounded with objectivity (whereas subjective testing exists) or automatibility (whereas manual testing exists). So, what is testable? what's not?

Discussion materials...

From this thread, the latest proposed definition was:

  A proposition is testable if there is such a procedure that assesses the truth value of a proposition with a high confidence level. Whether the confidence level is measurable and what confidence level is high enough depends on the proposition and its framework.

(the testability question sure enough surfaced again in a later thread on www-qa)

This proposition came from Alex Rousskov, with a precision from Al Gilman. An important point that it makes is that testability is relative to the context in which it is used; an assertion can be qualified as testable in one context, and not in the other. [@@@What defines this context? What implications does it have on the way a technology is designed?]

Once we have an acceptable definition, it should be added to the QA Glossary.

so... then this is a ProxyTopic? --DanConnolly
 no, it should get more data than the glossary, esp. how to make something testable, noodling about the relative context of testability... --DomHazael