What is Intelligence and How Do We Measure It?

In its most general definition, Intelligence is simply the ability to learn from experiences, solve problems, and use our knowledge to adapt to new situations. These kinds of intelligences can vary widely from person to person and even from day to day within the same person. In most aptitude tests, researchers study what is known as "school smarts," or the ability to learn and remember material. School smarts have been shown to correlate with intelligence overall, but they are not truly the same thing.

Intelligence Testing

Psychologists define intelligence testing as a method for assessing an individual's mental aptitudes and compare them with others sing a numerical score. Alfred Binet in 1906 developed the first intelligence test for school children in France in order to see if they would succeed in school. In 1916, Lewis Terman in the US adapted Binet's test for American school children and named it the Stanford-Binet test. This test is still used today, though in a revised form.

Intelligence Quotient

Lewis Terman, for the results of his test, devised the system that we still use today, called the Intelligence Quotient (or IQ). An IQ is discovered by dividing the mental age of the individual, meaning the score that most people would score at that age, and the chronological age of the individual and then multiplying that by 100. Therefore, if someone took the test at age 8 and scored what an average 8 year old would score, then there IQ is 100. If they were advanced for their age, their IQ would be larger than that.

Important Features of an Intelligence Test

Intelligence tests are very difficult to create because they must maintain many different truths in order to be useful. First of all. an intelligence test much use standardization. That means that the test is given to a sample of future test takers in order to establish a basis for meaningful comparison. It means nothing to say that your mental age is 8 unless you know for sure that most 8 year olds score at that level. A standardized test (such as the SAT) should have a bell curve in its results. This means that the majority of the test takers scored in the middle of the test and fewer and fewer scores were in the extremes.

Secondly, you must make sure the test is reliable. It must give reliable results throughout the entire test. One method for testing this is to ask the same question twice throughout the test to ensure that the test is getting accurate results out of the test taker. A test must also give roughly the same score to the same person if they were to take it again to be reliable.

Finally, a test must also have validity, meaning that it actually assesses what it says it is supposed to assess. This largest danger with this is that the test may not in fact measure intelligence but a certain biased knowledge base. Many tests have had to be revised because they have serious biases to certain racial or ethnic groups over others. If a test taker does not know a certain expression or is not familiar with a certain cultural fact, test results may be skewed. Test preparers work hard in trying to avoid this.

Intelligence tests cannot be given too much power in determining an individual's potential, but they are a rough measurement of a person's ability to succeed.

Source: http://en.wikipedia.org/wiki/Iq