Intelligence Quotient (IQ): defined originally as mental age divided by chronological age, multiplied by 100. On contemporary intelligence tests, the average performance for a given age is assigned a score of 100. The concept behind IQ was originally designed as a practical guide for teachers; identifying slow learners in need of special help, however it was developed as a numerical measure of inherited intelligence. However, the IQ test isn't the only intelligence evaluation test available. The Stanford-Binet intelligence test is an American version of Alfred Binet's intelligence test used on English schoolchildren to evaluate their mental age. The Stanford-Binet test measures, Fluid Reasoning, Quantitative Reasoning, Visual-Spatial Processing, Working Memory and the ability to compare verbal and non verbal performance. Also there's Wechslers' Adult Intelligence Scale.