Just got out my son's report. There are 10 tests (I think there are 3 more for extended). The individual scores are used to calculate 5 cluster scores - verbal ability, thinking ability, cog efficiency, phonemic awareness and working memory. From the written report it looks like cognitive efficiency includes processing speed and short term memory and I'm guessing working memory means just that. So lower working memory and processing speeds could potentially affect two cluster scores.
However the scores are calculated using a computer analysis set up so it is impossible to tell haw they are calculated or what weighting is given to each raw score. If you trust the tester I would just go with their professional opinion as to which test to use.
Good luck.
