Age equivalents
Expressed with a "dash"(-) between years and months of age.
What would be the largest number that would appear after the dash? (11)
If Jim has an age equivalent of 12-5 on the Math sub-test of the Metropolitan
Achievement Test (MAT), what does that mean? (He performed as well as the
average kid who is 12 years, 5 months of age)
Grade equivalents
Expressed as whole number separated by a decimal point.
Why expressed in tenths of a year? (Two months off for summer break)
If Janine's score on the vocabulary sub-test of the Stanford Achievement
Test is a "6.3", what does that mean? (She scored at a level
equal to the average kid who is in the 3rd month of 6th grade)
Interesting Points
Many tests create their norm groups by testing students within a few
weeks of their birthday. So if one of your students scores between
the average (mean) scores for a 10 and an 11 year
old, s/he'll be given an age equivalent score of 10-6 even though no 10
year 6 month old kids ever took the test (when norms were
being developed).
What is that estimation called?
"Interpolation" ("quess-timated" inside of available scores)
Some kids who score above the mean of the oldest kids in the norm group will be given a higher grade equivalent even though no kids of that age took the test.
What is that estimation called?
"Extrapolation" ("quess-timated" externally of the available scores)