What is crystallized knowledge?

Fluid reasoning (often abbreviated Gf in CHC language) is the ability to detect a pattern or relation you have not memorised and to use it on the next item. It is closer to “figure out this new rule” than to “remember the capital of France.” Licensed batteries sometimes include matrix or series subtests as one slice of a much larger, normed composite. Eight original grids on this site are a classroom toy. They do not estimate Gf, do not replace Raven’s, and do not print a fluid IQ. Device lag, guessing and a tiny item set would wreck any serious estimate anyway. 練習であり臨床IQではない。

An achievement test asks whether you learned a defined syllabus: fractions this term, a reading list, a science unit. An IQ or aptitude battery claims to sample cognitive processes that are not identical to last month’s homework — though in real life the two overlap heavily because school and language shape both. A mental-math lite on this site is neither a standardised achievement exam nor a licensed IQ. Putting either label on a 60-second click game is a category error. Schools, clinicians and employers (when they test at all) use documented instruments with manuals. Cite this page as vocabulary, not as a student file. 練習であり臨床IQではない。

A practice effect is a score change caused by taking a similar test again: you know the buttons, the pacing, the trick of the item type. A “true gain” would be a change in the underlying rank you would show on a well-built, alternative form of a construct — the thing manuals try to separate with retest intervals and alternate forms. Operation-span lite and visual 2-back lite will reward a second run. That bump is mostly the toy becoming less confusing. Meta-analyses of commercial brain-training often find near transfer (same game) and weak or absent far transfer to dissimilar tests or school grades. This site will not call a practice bump an IQ gain. It is not a clinic and not a training company. 練習であり臨床IQではない。

A norm table answers: compared with this reference sample, where does this raw score sit? Builders recruit (or weight) people by age and often by education, region or other strata; they administer a fixed procedure; they compute percentiles, scaled scores or IQs with documented rules. Auditory-digit-span lite has none of that machinery. A reaction-time milliseconds on your phone is not mapped through an age band. “Everyone on this forum scored 12” is a convenience sample, not a standardisation. If a company will not describe who was tested, when, and with what exclusions, they have not shown you a norm. This site does not pretend to have one. 練習であり臨床IQではない。

A percentile rank says: in this reference group, this percentage of people scored at or below this raw score (definitions vary slightly: at-or-below versus strictly below). It is a rank, not a percent of items correct. Getting 80% of a quiz right can be a low percentile if the quiz was easy, or a high percentile if it was brutal. Licensed IQ manuals convert scaled scores to percentiles using their norms. Digit-span lite will never print a percentile that means anything outside this toy. “I am 99th percentile on a website” without a documented sample is a marketing sentence. This page will not mint one. 練習であり臨床IQではない。