Wechsler Adult Intelligence Scale. Wechsler (1939)-“Intelligence is the aggregate of global capacity to understand the world, think rationally and use resources effectively when faced with challenges.” 

Wechsler Adult Intelligence Scale (WAIS), has received some adverse criticism for the 1939 version. The principle changes are in the improved content, extension of the standardization population sample, and improved direction for administering and scoring. WAIS, has six subsets that constitute the verbal scale and five in the performance scale. It is used for 16 to 64 years and takes one hour. As below 

Information test : This test consists of items of information covering a wide range. It consists of 29 questions covering a variety of topics which an adult should know about the virtue of having lived in a culture. Along with vocabulary, the information test is less affected by ageing or pathology. Still, the repressive person will often poorly perform while the pedantic and obsessive individual will score higher often giving pretentious responses. 

Comprehension test : Includes fourteen items in which the subject is asked to explain why certain practices are followed, to interpret proverbs and what should be done under such circumstances. For example, if one finds a stamped addressed envelop on the street. 

Arithmetic test : It requires the subject to solve fourteen problems, found in the grade- school arithmetic tests. Problems are orally presented and paper and pencil cannot be used. 

Similarities test: Consists of thirteen items which requires the subject to state how two things are alike. 

Digit span test : Short term memory for lists of digits starting from three to nine digits, which are orally presented and must be immediately repeated back. 

Vocabulary test : Requires the subject to define forty words of increasing difficulty. Vocabulary is the best single measure of general intelligence. It correlates most highly with full scale I.Q.

Performance Scale : Digit symbol is a code-substitution test which has often been used in non-verbal test procedures. In this, there are nine symbols paired with nine numbers, along with the key before the subject. He must fill in as many blanks are the answer sheet as he can in one-and-a-half minutes. 

Picture completion test: In this the subject is asked to fill the missing part of a series of twenty one drawings. Close attention is required for this test. 

Block design test : In this test their are eight items. Picture Arrangement: As the name itself reflects in picture arrangement test the subject has to arrange the picture in a manner of storytelling. 

Object Assembly : In this test fragmented objects have to be assembled, in their original wholes. The active wall can be adjusted in one hour.