|My soapbox. Except I wear cuter shoes!|
Why was this a problem for me?
Age and Grade Equivalents are NOT real numbers. They look like numbers, they sound like numbers, but they are not numbers. Please don't treat them like numbers. They are impostors.
What can an age or grade equivalent tell you about a student's performance? Not much. Say a student is in grade 8.2 (eighth grade, second month of school) and they earn a grade equivalent of 6.8 on the calculation test of the Woodcock Johnson III. This DOES NOT mean that this student is 1.4 grades behind in calculation. Why? Because they are not real numbers, so you can't do math with them like they are real numbers. All you know is that they earned the same number of corrects as the average student in the 6th grade, eighth month in the norm sample. Chances are that a 6.8 in calculation will fall within the average range for and eighth grader once you look at their percentile score or standardized testing scores.
Say this same student was tested last year and his calculation score was a grade equivalent of 4.2. Can I say that he made 2.6 grades of improvement in calculation? NO. Why? Because age/grade equivalents are NOT real numbers and should not be treated like numbers.
So why are they used? I think they are used because some people think that parents understand age/grade equivalents better than percentile or standard scores. I think that they offer a false sense of understanding and it is way more valuable to educate parents on standard scores. If you'd like scores that really are numbers and can be used to compare for progress purposes, use standard scores.
Repeat after me. "Age and grade equivalents are NOT real numbers."
*steps off soapbox*