For example, a child might have to miss three questions in a row before the tester quits asking questions. However, the tester runs out of questions before the child can miss three in a row. This does not mean that the child hasnt missed any questions. He or she may have missed one, answered a couple more, missed two, answered more, and so on until no more questions are available.
IQ scores for children who hit the ceiling of an IQ test may not be accurate; that is, they may be too low because the children were unable to continue answering questions until the questions became too difficult for them to answer. Of course, the score could also be correct, but when children hit the ceiling of a test, all we can know is that the score they received is their lowest possible score. Their actual score could be a little or a lot higher, but it is impossible to know.