You might have heard that somebody has obtained very good IQ score. Some may even show you their certificates to prove that they have got more than 120 IQ score. Higher the score, higher the intelligence level is presumed. However, such claims and assumptions are baseless, false and misleading. The highest IQ test score in one IQ test may not be equivalent to an average score of another test.
A good IQ score is a relative term. The initial score obtained by answering the items correctly is called a raw score. It is useless unless interpreted in meaningful terms by following the established norms. Even when two scores are processed through the psychometric principles, you can’t ignore the following important issues before determining a good IQ score:
Name of the IQ Test
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Unfortunately, the psychologists have not succeeded yet to develop a perfect system of comparing two IQ scores got from different IQ test. Naïve comparison of two digits, however higher they may be, can’t help you to determine a good IQ score. First of all you need to know on what IQ test on which the highest score was obtained.
Difficulty Level of the Items
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The second problem to determine a good IQ scoring is the difficulty level of the test on which the claimed good IQ score was obtained. Your score will decline with the increasing difficulty level of the items being offered. It is possible that you get two different IQ score with two tests having same label. One reason for this variance would be the difficulty level of the items. The test developers vary the difficulty level of the test with the change of age, education and some other important factors.
Content Variance
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You can find a number of tests with the same name but with different content. Even when you obtain 120 IQ score on an IQ test of verbal capabilities, you mayn’t claim the same level on another test of the same label containing mathematical items. General IQ tests try to develop items from all categories of intelligence but modern day testing industry is getting more specialized with every passing day. You need to consider content variation while determining any score a good IQ score.
Time and Age Differences
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You may have got 120 IQ score in your fifth grade, 115 in sixth and 110 in seventh grade. Apparently, your intelligence level is decreasing with each passing year. However, the actual position may be entirely different for a number of reasons including the label of the test, the difficulty level or even difference in the content. You can’t be sure that your highest IQ score is your good IQ score.
Difference of Standard Deviation Units
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Originally, the mental age (MA) was considered sufficient to measure your intelligence. It soon proved useless and the term of intelligence quotient (IQ) was introduced. It was nothing more than a simple ratio of the mental age to the chronological age, multiplied by 100 to eliminate decimals. A score of 100 was considered an average IQ score and any deviation could place you in the range of above or the below average population. The system worked well unless it was proved that standard deviation doesn’t remain constant throughout your life.
Now different IQ tests use different levels of standard deviation. It is possible that one test use a standard deviation of 15 and another of 20. In such situation two apparent equal IQ score can’t be interpreted into equal level of the intelligence. Thus determining a good IQ score becomes further difficult.