Cohort 2 were born in 1953. In the spring term of 1966, the collection of data from the project's second cohort began and then applied to students born in 1953. The total number in the questionnaire is 10,723. As five years earlier, the majority were in 6th grade in the compulsory school system, but due of the introduction of compulsory school gradually, about 80 per cent now belonged to this school form, while only 20 per cent belonged to the older school form, the primary school.
In 6th grade, the students completed cognitive tests of an intelligence test nature, containing tasks of a verbal, inductive and spatial nature. At the same time, the students filled in a questionnaire with, among other things, questions about the school and plans.
Information about schooling, for example school form, class type, class structure, class character, year and grades are collected annually from 6th grade. As well as information about certain personal circumstances. Results from standardized knowledge tests are included. The tests are not the same as in 1961. Furthermore, it can be mentioned that partly different tests were given in compulsory school and primary school, respectively.