The acronyms come up as soon as you look into the subject, without it being clear what they cover. Here is what these instruments actually are, and what separates them from an online test — including ours.

The Wechsler scales: WAIS and WISC

These are the most widely used clinical instruments in the world. WAIS for adults, WISC for children aged six to sixteen, WPPSI for younger children. Each is revised and restandardised regularly — a necessity, for the reasons set out in our piece on the Flynn effect.

Administration is one-to-one, face to face, over two to three hours. These are not questionnaires: they are varied tasks — arranging blocks, completing series, answering spoken vocabulary and comprehension questions, repeating digit sequences, crossing out symbols against a clock.

The output is not a number but a set of indices, usually four or five depending on the edition:

  • verbal comprehension — vocabulary, reasoning about concepts;
  • visual-spatial and fluid reasoning — manipulating form, abstract logic;
  • working memory — holding and manipulating information briefly;
  • processing speed — pace on simple, repetitive tasks.

The overall score is only computed when the indices are reasonably consistent. Where they diverge sharply, the psychologist often declines to produce one — rightly: the average of a very high index and a very low one describes nobody.

Raven’s Matrices

A single principle across several difficulty levels: a grid of abstract figures, one cell missing, six to eight options. Not a word, no complex verbal instruction.

The instrument is heavily used in research and in international settings, precisely because it crosses language barriers. It exists in a standard version, a coloured version for children and older adults, and an advanced version for the upper range.

Its limitation is the flip side of its strength: it measures one facet, inductive reasoning over figures. It says nothing about verbal ability, memory or speed. An assessment is never just matrices.

What really separates an assessment from an online test

The difference is not primarily question quality. It comes down to four things.

Standardisation. Clinical instruments are calibrated on representative samples of hundreds to thousands of people, by age band and by country. It is long, expensive work — and it is what gives a score its meaning. No free online test has that, and those claiming otherwise are lying.

Observation. The psychologist records more than answers: strategy, persistence after failure, impulsivity, requests for help, spontaneous commentary. A good share of the clinical information lives there, and a screen captures none of it.

Controlled conditions. Same room, same materials, same instructions, same trained examiner. Online, you might be on a train, interrupted, or with two other people in the room.

Interpretation. A number is not a diagnosis. The psychologist places the profile inside a history — educational, medical, family — and it is that crossing that produces something useful.

Why these tests are not public

Two reasons, both solid.

First copyright: these are protected works, published by specialist houses. Reproducing them on a website is unlawful. It is why every item in our test was written specifically for this site, and why you will find neither a Raven matrix nor a WAIS subtest here.

Second validity: a test whose items circulate freely loses its value. If you saw the questions yesterday, your score measures recall. That is why access to clinical instruments is restricted to professionals with documented training — a rule sometimes read as protectionism, but one that protects the measurement.

So what is an online test for?

Satisfying a legitimate curiosity, and giving an order of magnitude. That is a modest use, and it is exactly what the tool can offer.

What we can do seriously: original items, an explicit scoring model, a stated confidence range, a profile by area, and a full worked correction. What we cannot do: produce a result with diagnostic or administrative standing.

If your question is concrete — school difficulties, a doubt about a particular profile, a placement decision — no online test will answer it. If it is “roughly where do I sit, out of curiosity”, our full test does the job.