Introduction to IQ testing

Intelligence is a complex multifaceted measure of an individual's function on a range of verbal and non-verbal measures and can contribute to a greater understanding of how a child makes sense of their environment. Intellectual ability reflects a complex range of cognitive functions including attention, auditory, visual and tactile perception, language, memory and executive function. The most frequently used measures of IQ for children are the Wechsler scales although these are only sensitive for abilities 2 standard deviations above or below average. Interpretation of IQ should also consider social and medical history as well as linguistic and cultural background. Testers should take into account the ability to plan and organize behaviour, enthusiasm, impulsivity, anxiety and persistence. Although an estimate of ability can be completed using a limited number of subtests from an IQ battery or a single vocabulary and/or problem solving tests these are not a substitute for a comprehensive assessment of cognitive ability. IQ tests can be used to predict expected performance on reading, maths and language skills which can be helpful when young people are having difficulty in school. When assessing literacy the relationship between accuracy, speed and comprehension is important whilst differences between written and verbal maths skills should be considered when there are problems with numeracy.