• Intelligence - An organism's ability to learn and behave adaptively.
• IQ - Intelligence Quotient - The score on an intelligence test.
• Ability - What one is capable of doing.
• Achievement - What one has done, an actual measurable performance. All tests measure some achievement / performance on a particular task at a particular time under particular circumstances.
  
• Reliability - consistent results in performing a measurement.
• Validity - the extent to which something actually measures what it is said to measure.

We don't currently have a good grasp on exactly what intelligence IS.
How shall we measure a thing, or a characteristic whose definition we don't even really agree upon?

Basic idea of Intelligence Testing:
    If we test on elements of the culture that all people have been equally exposed to, then the more intelligent will have learned more of those elements.
    This is good in theory, but has obvious flaws in the notion that there is anything all people of a society are equally exposed to!

TYPES of TESTS:

IQ - measure by comparing mental age by chronological age

 Skills - measure ability to perform on task-relevant skills.

Two of my favorite quotes about Intelligence Testing:

This intelligence testing business reminds me of the way they used to weigh hogs in Texas. They would get a long plank, put it over a cross-bar, and somehow tie the hog on one end of the plank. They'd search all around till they found a stone that would balance the weight of the hog and they'd put that on the other end of the plank. Then they'd guess the weight of the stone. (John Dewey (1859-1952) American teacher, philosopher, reformer)

Intelligence tests are like weeds; they won't go away and you can't improve them with cultivation. (anonymous)

• IQ shows some stability over years and predictability, but:
• IQ scores can fluctuate considerably. McCall et al. found the average change between 2:6 to 17 years age to be 28.5 IQ points with 1 child in 7 changing at least 40 points! (Origins of intelligence: infancy and early childhood. By Michael Lewis  Google Books: Link )
  
• IQ des not address motivation or interest.
• Testing does not generally make accommodation for learning disabilities, language (such as non-native speakers), test and performance anxiety.
• Test results can label a child and determine future educational and occupational opportunities.
• Kids who are older in a class have a developmental advantage over those who are younger in the class.
  
• IQ is moderately predictive of occupational success, but is not a guarantee - prior job performance and motivation are often better predictors.
• Individuals with a high IQ tend to be well adjusted, but high IQ does not guarantee good adjustment or success. Home environment plays an important role.
• Many mildly and moderately retarded individuals (40 - 70 points IQ) lead productive lives and experience fulfillment.
• IQ tests predict current and future grades moderately well.

Interesting Internet Sites