Gifted Issues Discussion homepage Forums Identification, Testing & Assessment Reliability of CogAT scores over time

I now have three consecutive years of CogAT scores on my child, with vastly different results.

Composite Score:

First Grade- 105 (highest= math, lowest= verbal);
Second Grade- 122 (highest= math, lowest= verbal) NNAT= 122;
Third Grade- 135 (highest= nonverbal, lowest= verbal)

Does anyone else have multiple years of data for their child on this test? I'm curious how common it is for scores to vary this much.

In case anyone is wondering why he took this test three years in a row, we had him tested for giftedness in first at his teacher's suggestion - he did not qualify (obviously). In second they screened all kids using the NNAT and then tested kids in the top 5% on that test at the school with the CogAT - he qualified for gifted based on his math score (96th percentile) and teacher ratings/work samples. In third they test all currently gifted identified kids for entrance into the highly gifted program, which I doubt he will qualify for based on his scores.

I've seen multiple CogATs for hundreds of children over the years, and it is quite common for them to vary by ten or twenty points either way, and not too unusual for them to vary as much as 30, as your child's did.

I wonder if there was a practice effect.

I think the third grade version changes from being picture based to the child needing to read the test on their own. So it could be showing simply that your child does better on certain versions of the test. My DD was the opposite. I don't have her Kindergarten CogAT scores but I know she was highest in non-verbal and her overall score was high enough that they allowed her to grade accelerate. Then she took the third grade version in second grade (they used to give the kids the test for a grade level ahead) and she had problems with the timing bringing down her scores dramatically. That time her verbal score was the highest and it had been the lowest on the K test.

CogAT is not reliable but even real IQ tests aren't necessarily reliable in young children.

Yes, I think that the format change is part of it. The counselor told me that the k-2 version is picture based and untimed vs. a timed test with words and numbers for third onwards. She also told me that the scores are not really supposed to change that much, but that they often do. The non-verbal part of the test is the section I would expect to change the least though (it would still be pictures), and that's where his score jumped the most. Maybe it's all the hours of minecraft that he plays

I think the first grade scores are probably the most invalid - it's the first test he had ever taken on the computer and I suspect he just wasn't mature enough at that point to really try his best. I also did not explain to him why he was taking the test that year which I think effects effort. He's also a fast finisher, so I suspect he got distracted while waiting for the other kids to finish so that the test administrator could move on to the next question.

Regarding a practice effect - I think that's possible too, though a friend who also has taken it three consecutive years had her scores go down compared to last year.

My son is obviously stronger in math than language arts, so the test is picking up a valid difference there. I don't know what to think about his non-verbal abilities though - that's not something I'm really tuned into and doesn't match up with a specific school subject.

I find it all very interesting though and wish that the makers of the test would study score reliability over time.

He also just could have been a late bloomer.

I received notice today that my son was accepted into the district's highly gifted program! His scores are in the moderately gifted range, but I'm guessing that the district doesn't have enough 140+ kids to fill an entire class. His achievement percentiles and grades are also very good so I'm sure that helped. It's a great program from what I hear so I am very excited for him!

That is exciting! Congrats to your son, I hope that the program turns out to be all that it can be.

Thank you! It is a huge relief that he can get a more challenging curriculum without us having to pay a ton of money for private school.

That's very excited news! I would love to hear how different you find it that his current gifted program as he gets going.