The mental age is determined by
performance on the test (for instance, a
5-year-old performs like most other 5-yearolds).
The chronological age is the actual age
of the child in years so that the average IQ
for a given age group is 100. The child’s IQ
score is compared to scores of many other
children and ranks a child’s ability compared
to others. In other words, the IQ is a normreferenced
test that measures the child’s
score against an established norm.