u/BenefitPersonal4959

Been seeing debates about this pop up a lot and wanted to actually look into what "reliable" means in a testing context, since people seem to use it loosely. Turns out reliability specifically refers to consistency, if you retook the same test under similar conditions, would you get roughly the same score. Major standardized tests (WAIS, Stanford-Binet, etc.) actually score really high on this, usually in the 0.90+ range on a 0-1 scale, which is considered excellent by psychometric standards, way higher than most personality or aptitude tests.

That said, reliability isn't the same as accuracy for a single test-taker on a given day, stuff like sleep, stress, test anxiety, or even just an off day can still shift your score by a few points. So the tests are consistent as instruments, but that doesn't mean any one score you get is a perfect permanent snapshot of your ability.

Curious if people here have noticed variation retaking the same or different tests, or if scores have stayed pretty consistent for you?

Been seeing this come up a lot in different threads and wanted to actually dig into what "bias" means in this context, because I think people use the word differently depending on the argument they're making. Turns out psychometricians actually have a technical definition for this, "test bias" specifically refers to whether a test predicts outcomes (grades, job performance, etc.) equally well across different groups, not just whether average scores differ between groups. Most large-scale studies on major standardized IQ tests (WAIS, Stanford-Binet, etc.) find they're not statistically biased in that specific sense, meaning the test predicts outcomes similarly across demographic groups even when average scores differ.

That said, there's still legitimate debate around stuff like cultural/language loading in certain test items, access to test prep/quality education affecting scores, and whether socioeconomic factors get baked into results in ways that aren't really about "intelligence" itself. So genuinely curious what people think, is "bias" mostly a misunderstanding of statistics, or are there real, valid concerns baked into how these tests are built?

Always see people throwing around "Einstein had an IQ of 160" like it's a known fact, but the more I looked into it the more it seems like nobody actually knows for sure. He never took a standardized IQ test in his lifetime, at least not one that's documented anywhere.

So where do all these numbers (160, 190, whatever) even come from? Feels like it's just estimates based on his achievements/work, which kind of goes against the whole "achievement isn't the same as intelligence" thing people bring up all the time.