bill cobbett wrote:Friends, for those who still think that IQ is a measure of intelligence, here's a truism... Take a large enough sample and you can't get a much bigger sample than one of nation size and the average IQ of the large sample will be 100.
Honestly seen some rubbish refs posted on CF over the years and this one goes straight in to the Top 10 rubbish links.
Bill the tests are supposedly standardised so a given score will measure the absolute intelligence of a person . : it is then statistical tricks which are applied to convert the scores in to averages or centiles where d in theory a score of 100 should correspond to the mean median and mode of the intelligence of the group against which the tests were standardised.
here is something from a pro on the topiv
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Intelligence
Cognitive abilities or intelligence is better defined by Wechsler (1944) as the “capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment”. It should not be confused with the attainment which a child does in fact achieve since laziness, illness, anxiety or a variety of other factors may be affecting the level of attainment. In general a psychologist is not concerned with measuring attainment as this is usually assessed by school tests and examinations by teachers comparing a child with his peers irrespective of potential. Intelligence consists of a general factor underpinning all purposeful thinking and behaviour together with certain specific factors. What intelligence tests measure is important; “the capacity of an individual to understand the world about them and their resourcefulness to cope with its challenges” – Wechsler 1975. Intelligence is measured in terms of Intelligence Quotient (I.Q.). The national average is 100 with 34% of the population having IQ’s between 85 and 100 and 34% of the population having IQ’s between 100 and 115. This is known as the “average” range. About 16% have IQ’s above 115 and about 3% above 130.
The Wechsler Scales were selected to measure general ability with subtests that vary in content. For example, some subtests require knowledge of words and comprehension of verbal relationships; others require working memory for recalling numbered sequences or reasoning with arithmetic or spatial stimuli. Wechsler (1975) noted that "... the attributes and factors of intelligence, like the elementary particles in physics, have at once collective and individual properties". Therefore, despite the individual demands of specific subtests, they form a cohesive whole that is expressed by the test's Full Scale score, which reflects the overall concept of general ability.
The WNV, published by The Psychological Corporation in 2006 is an individually administered, clinical instrument restricted in its use to qualified psychologists and is designed to measure the general cognitive ability of examinees aged 4 years 0 months through 21 years 11 months. The test was developed so that general ability could be measured using a multi-subtest, comprehensive format that eliminates or minimizes verbal content (e.g., Vocabulary). Pictorial directions were developed to communicate the demands of the subtests with little or no verbal instructions. The characteristics of the WNV, and the manner in which it is administered, makes the WNV a test of general ability that can be used with populations that are diverse in terms of language, educational, cultural and socioeconomic backgrounds, as well as certain conditions, such as language disabilities and hearing loss. These features make the WNV a test that is highly portable across cultur¬ally and linguistically diverse groups as well as national boundaries.
Other versions of the Wechsler Scales (WISC 1V etc) measure general ability with a combination of verbal and performance subtests; however, the WNV is designed to measure general ability with only non-verbal tasks. One advantage of using non-verbal tasks is that the need for receptive language skills is minimized. Another advantage is that the influence of expressive language and mathematic skills on the examinee's test performance is eliminated.
When reviewing scores, remember that no test is perfectly accurate. Any person might score slightly higher or lower if tested again on a different day.
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