The CogAT will be scored on both age and grade norms. Which score is used by the school depends on local conditions. She probably shouldn't be taking the exact same form two years in a row. The publishers have already factored in some retest effects for adjacent years (which have some overlapping items), but a one-year interval for the same form wouldn't be optimal.
Yes, on the CogAT7 there is a significant difference in test format between second grade and third grade. The K-2 (age 5-8) test is entirely pictorial (with one optional verbal section), with orally-presented directions, while the 3-12 test has a more conventional text-based verbal section. They are supposedly continuously scaled, and supposedly measure comparable verbal reasoning skills, based on their factor analysis.
