Thomson discusses the limitations of intelligence testing, and its positive qualities, citing its objectivity and scientific basis.

He outlines the processes involved in trialling the tests to establish their suitability and reliability, describing how the final order and content of the paper is decided; the difficulties involved in obtaining a representative sample of children; the need to incentivise children to do their best in the trial test, and the process of standardisation of test results and the creation of norms for each age group. He also touches upon the relationship between age and test performance within pupils at the same educational level.

Thomson describes the distribution of IQ levels shown by such tests, and how teachers might use these to predict and plan for educational attainment.