Intelligence testing

INTRODUCTION ( Psychometrics)
The term 'IQ' or 'Intelligence Quotient' describe a score in an intelligence test. While it used to be arrived at by dividing the mental-age by the chronological age, this procedure is no longer recommended. In most variants of these tests, a score of 100 means you are 'normal'. Of course, 'normal' depends on a whole lot of cultural factors - like whether you can understand the test to start with. The point to understand is that while those getting more than 100 are sure to be gifted in some way, those who get less are not necessarily mentally challenged. When used, approximately 95% of the population get scores between 70 to 130.

TYPES OF TESTS ( not comprehensive)
1. Wechsler tests (WISC and WAIS) - Wechsler Intelligence scale for Children (WISC) and Wechsler's Adult Intelligence Scale (WAIS).
2. Stanford- Binet test
3. Peabody picture vocabulary test ( measure of verbal intelligence)
4.Ravens progressive matrices ( reasoning and perceptual evaluation)
5. Catell's intelligence tests
Binet & Simon developed the first useful intelligence test in 1905. They used a 'common-sense' approach in deciding what type of questions to use, and chose a wide variety of tasks normally associated with intelligence. They then went on to use standardization samples to establish test norms within age groups - giving rise to the term "mental age".
Stern, in 1912 was the first to attempt at constructing an intelligence quotient. He wanted to develop one that reflects a person's mental age in relation to their real age. He therefore derived the formula "IQ = Mental Age / Chronological Age * 100", but this formula is flawed because it states in adulthood intelligence levels plateau, yet chronological age continues to increase, imbalancing the formula and causing the IQ level to actually start retarding.

TESTS RESULT CORRELATIONS
Intelligence test scores partially predict individual differences in school achievement, such as grade point average and number of years of education that individuals complete.
Test scores also correlate to some extent with measures of accomplishment outside of school.
Differences in genetic endowment contribute substantially to individual differences in (psychometric) intelligence.
Environmental factors contribute substantially to the development of intelligence Attendance at school is certainly important, but it is not known what aspects of schooling are critical.
The role of nutrition in intelligence remains obscure. Severe childhood malnutrition has clear negative effects.
Although there are no important sex differences in overall intelligence test
Scores, substantial differences do appear for specific abilities. Males typically score higher on visual-spatial and (around middle childhood) mathematical skills; females excel on a number of verbal measures.

BE WARY OF TEST RESULTS !
Psychometrics do not sample all forms of intelligence, obvious examples are practical sense, social sensitivity, personal skills. Conversely, it has enabled the development of some dangerous assumptions, some of which are mentioned below.

• They assume that the tests measure the capacity of a person's intelligence, whereas they actually only measure test score achievement, which is not necessarily the same thing.


• If low IQ scores are interpreted as measuring actual 'intellectual' capacity, it allows the educational system to write off underachievers as not having the capacity to do any better. This writes off the kids who are natural slow starters.


• Tests tend to label youngsters, stigmatizing the ones who don't do well and setting the scene for a dangerous self-fulfilling prophecy.


• It is important to remember that intelligence is very much affected by learning (within the limits of the individual) and therefore it is necessary to see intelligence as the effect of learning ?