I know that psychologists and others who are tasked with explaining GEs to parents always say not to pay any attention to them. And that's true, one shouldn't use GEs for placement because they don't indicate mastery. They only indicate the pathetic state of education in this country.
We only got GEs on the WJ-III and percentiles for the MAPS, ITBS, etc. so I haven't been able to directly compare how the GEs would have lined up for my kids, but that is interesting.
I would also say that I don't know that super high GEs are only due to our educational system being broken. These types of tests are often multiple choice and don't cover nearly as broad of content as does curriculum nor do they ask children to, say, write essays, develop a thesis, apply learned material, etc.
For instance, one of my girls had GEs of 18+ on various parts of the writing and reading tests on the WJ-III when she was a young 7 y/o. While she's very good at language arts and consistently tested in the 99th percentile on tests like MAPs, SRI lexile, etc., I am quite certain that she was not at a post graduate level in anything at that age. What she was was able to apply what she did know well enough to answer multiple choice questions well, write simple sentences in a grammatically correct manner, etc. This translated to some very high GEs due to test limitations probably more than low academic standards in the US.
