I was working on explaining to another a parent about how tests differ and results can vary, when I came up with a quick analogy. (I am sure someone else probably already has used this). Its like a picture, you don�t see everything about the person, only what they show you in the picture. The picture needs a good camera (the test) and a good photographer (the tester). A good camera and a good photographer need a cooperating subject, or have the ability to bring out the best from the subject. Not all photographers work best with all subjects. All three are part or creating a good picture. Many times you will need different pictures to get a better view of what the subject can offer.

Good analogy. One things I've come to believe over time as well is that it isn't only incorrectly poor results that can come from one of those pieces being off. For instance, it is fairly clear that a subject who is moving isn't going to be as easy to photograph even if the camera and the photographer are good or that a poor photographer might lead to a poor photograph.

However, and others may disagree with me here, I lean toward believing that a photo can be artifically good to a certain extent as well -- photoshopping to use your analogy. A photographer can also create some degree of misrepresentation in his pictures through misuse, accident, an optical illusion, unusual lighting, etc.

I say this not b/c I think that any of us has wrongly ided kids but b/c I've seen a lot more fluctuation on IQ and other ability scores than I had been prone to believe would exist in the past and I've seen kids tested by people who were determined to find giftedness somewhere who found something other testers did not (and I'm a skeptic in some of these situations).

I belive that younger children may be able to do better then expected on some achievment tests. I am not so sure on standard IQ tests. A child that is exposed to more math at a young age may do better then one that was not, with both having the same IQ. I have no facts to back this up, just based upon how an achievmenttest is structured.