Wechsler made the first attempt to construct an intelligence scale specifically for adults. Until his effort, most intelligence tests used with adults were not standardized for anyone over 18. 

"Discusses the construction and administration of tests of adult intelligence. The nature of intelligence, need for an adult intelligence scale, mental age and I.Q., intelligence classification, as well as mental deficiency and deterioration are examined. The factorial composition of Bellevue Intelligence Scales is discussed. Specifically, chapters on the selection and description of tests, the population used in standardization, limitations and special merits are included. Clinical evaluation of brain damage and the use of the tests in counseling and guidance are also discussed" (PsycINFO Database Record).