David Wechsler’s tests on intelligence took a very different approach. Identify that approach, and explain why his tests are so popular today.
Intelligence tests are used to examine such mental processes of a person as reasoning, understanding and the ability to recall information. If correctly administered, intelligence tests are used to detect impairments of learning. There are two widely used tests developed by Stanford-Binet and Wechsler.
An American psychologist David Wechsler devised his own version of intelligence tests, as he said that his predecessor Stanford-Binet put a lot of emphasis on verbal abilities. Wechsler’s test includes separate I.Q.s, which are designed to assess overall performance, and a verbal I.Q. The performance and verbal I.Q. s comparison may reveal problems, which are not always shown when using a test in which a single I.Q. is reported (David Wechsler). There are three Wechsler’s tests on intelligence - The Wechsler Intelligence Scale for Children, which is designed for intelligence assessment of kids, and The Wechsler Adult Intelligence Scale for intelligence assessment of grown-ups, and the Wechsler Preschool and Primary Scale of Intelligence. The tests should be administrated by a trained administrator. Wechsler Intelligence Scales introduces the following notable features: calculation of standard score, assessment which allowed determining performance with the help of nonverbal and verbal means, separate norms for adults and children, etc.
Characteristic features of such tests are raw scores that are converted to standard score and added to yield a performance, verbal and an overall IQ scores. The test’s points are based on age, rapid completion means additional points, and the test contains only necessary subtests. The tests are conceptually divided into verbal and non-verbal performance. The publication of Wechsler Intelligence Scale for Children-Revised caused the emergence of a third factor. The fourth factor was revealed while clarifying the third factor structure. Analysis of factors is a multivariate analysis method, which requires the development of some non-metric alternatives in order to find order relations in psychological phenomena. Variables are represented as points in Euclidian space. The main idea of this approach is that the isomorphism between the interpoint distances in the Euclidian space and the proximity measures among the variables gives the possibility to observe intercorrelation matrix directly (Bilsky, Elizur 3-4).
To use and interpret the scales in the meaningful way, it is required to adopt an alternative approach, which combines research, hypothesis validation, contemporary theory, and measurement principles. Such approaches are necessary to assess a wider range of abilities than those accomplished through traditional methods (Personality and Aptitude Career Tests).
The Wechsler scales were later revised by the usage of standardization samples. They took into account the fact that they should be demographically representative of the United States population. Procedure, methods and concepts, which are present in the design of the Wechsler Scales, have guided lots of research in this field and are influential even nowadays.
IQ tests developed by Wechsler are very popular nowadays because they are easy to administer and compute, very easy to compare and revise if required. It means that is easy to switch from Wechsler test to another one; the tests measure person’s specific weaknesses and strengths and provides useful data for the personality profile; it gives the opportunity to compare functionalities of two hemispheres separately. Wechsler’s contribution to the field of intellectual assessment has been very substantial. His aim was to create tools, which are easy to use for clinical purposes. Nowadays his tests are useful tools to assess achievement skills, curriculum planning, education placement, diagnosis of learning disability, and clinical appraisal. New norms of the test allow the evaluation of disabled students. The Wechsler IQ tests are very important for job purposes.