FWIW, last year my DD took the STAR test twice in one day because they thought the first test didn't "take." In a space of that one day my daughter's STAR test varied by 2 entire grade levels. I agree that for the test to be useful it is good to look at the general trend over the course of the year. And, like Dottie says, kids should read whatever they are comfortable with. That being said, if the STAR test results are limiting your DD's choices of books available for checkout from the library to books that aren't at the level at which she is comfortable reading, then I'd talk to the teacher and/or the librarian.
