General knowledge tests (GKT) examine knowledge which is not usually associated with institutionalized education, but is part of everyday communication and often found in the media. Indirectly, they measure the ability to acquire knowledge and, in this sense, coincide with the definition of crystallized intelligence as a measure of acquiring and using knowledge. Three studies using relatively short versions of the GKT on various samples in the Republic of Croatia, which were part of a larger battery of cognitive tests with a similar number of items and reliability, the GKT has consistently shown the greatest projection on the principal component of these tests. This answers the question of why we need the GKT: carefully selected general knowledge items can serve as a measure of Gc. When to use the test has several options. The first is in situations where there is a lack of time – 50 items require less than 20 minutes. The second is a formal reason – in cases of resistance to or a ban on intelligence testing, using the GKT goes over well. The third is a humane reason – due to its form and title, it causes less stress and test anxiety as it is easier to be uniformed than unintelligent as far as self-respect is concerned. There is also the question of how to use the GKT. Some items become recognized, some lose their importance with technological advances and socio-political changes, new potentially good items appear so the GKT needs to be revised every 5 to 10 years. This is valid for the choice and range of general knowledge domains. As far as GKT calibration is concerned, with the aim of constructing tests of good internal reliability (which is necessarily lower than the majority of unifaceted classic intelligence tests), separate calibration is recommended in relation to gender and education (high schools, professional schools, tertiary education). However, in view of the increasing availability of general information, such a differential calibration may be subject to review.

Crystallized intelligence, gender differences, General knowledge tests, General information tests, test anxiety