First 239 words of the document:
Psychology unit 3 intelligence
Psychometric explanations for intelligence- Thurstone's theory
Analysed 56 tests that were given to 240 studnets who each did 56 tests from
Chicago University. He found there were 7 primary mental abilities that people
Verbal comprehension- understanding and defining words
Verbal fluency- using the correct words in the right context
Perceptual speed- judging similarities and differences between objects
Inductive reasoning- spotting patterns and making predictions
Spatial ability- visualising relationships between objects
Number- ability to solve arithmetic problems
Memory- remembering and recalling information
Based on evidence from 240 university students so has good population
validity as the sample is large, therefore the results should be valid.
Low population validity as it was only university students who are a
specific sample of the population. When the tests were performed on school
children he didn't find evidence for the 7 PMA's but did find more evidence
Carroll has calculated that about 50% of the variations in answers on the
original tests were down to `g' and about 50% due to the PMA's. For the
wider population, the influence of `g' increases.
The theory is not used much due to the fact that it is not very good at
predicting academic and occupational performance. Spearman's theory was
much better at these predictions.