Validation Process

How are IQ tests created?

Ever wondered how IQ tests are created?

In the present section, you will explore everything about the procedures behind the creation of the Brain Assessment Center IQ test (and behind any other online or offline IQ tests).

After Reading it, you will understand the most important test development concepts and you will know how all IQ tests work, including the Brain Assessment Center (BAC) IQ test and other reliable online/digital tests, the Raven’s progressive matrices or the Wechsler.

Let’s dive in!

In order to create a valid IQ test, it must fulfill two conditions (we are oversimplifying for the sake of simplicity, no pun intended): 1) The sample of testtakers must be representative of the general population (that is, of the overall/general population) and 2) The sets of items used must have psychometric validity.

(Again, the whole science behind it is more complex, this is just a simplification outlining the most important and remarkable factors).

Let’s explain these two points in detail.

A representative sample is a subset of a group that seeks to accurately reflect the characteristics of a larger group. For example, a university classroom of 50 students, 25 female and 25 male, could generate a representative sample of 5 males and 5 females (it is representative because the target variable of the example, gender, is present in the same proportion as in the larger sample).

Of course, gender is not the only variable that must be taken into account when developing IQ tests, the sample must be also representative for at least ethnicity/country, age and performance/intellectual ability.

The latter means that, since IQ tests generate scores by comparing your performance against the performance of others, these other testtakers must be composed of groups of all the existing intellectual/IQ levels. For instance, if your performance was only compared against Einsteins, your resulting score would be very low, below average, and that would be wrongly measured!

In the past, finding samples of testtakers who were also representative of the general population was very hard and costful.

However, Nowadays, thanks to the Internet and the new digital technologies, it is possible to obtain thousands of input data points (that is, thousands of participants) in a matter of days.

And thanks to the power of algorithmic classification, it is possible to assess and separate these testtakers into different representative groups, by variables such as gender, age, nationality or performance.

Last, “items with psychometric validity“, oversimplifying, means that those items are valid and reliable, or in other words, 1) that they measure what they are designed to measure and 2) that they always give the same (or very similar) results each time they are taken by a person with the same level of intellectual ability (that is, that they discriminate properly between different intellectual levels).

To conclude, let’s see what each of these points means more in detail:

-Validity: They measure what they’re designed to measure: there are several ways to psychometrically assess this property. In layman’s terms, what this means is that these items must assess IQ/intellectual ability, and not something different (e.g., plain knowledge or someone’s ability to dance).

-Reliability: if the real intellectual ability of 2 different persons is 100, then the test is reliable if these 2 persons have the same score or a very similar one (e.g., 105 and 97). If one had a score of 80 and the another one had a score of 190, then it would be unreliable.

If you want to find more about the idea behind the Brain Assessment Center and our mission, you can read our about section.