Re the WISC vs DAS:
First off, DAS subtest scores are usually reported as T scores (x = 50, SD = 10), which would make the verbal comp score 2.8 SD above the mean, or equivalent to about an 18 on the WISC, and the naming vocab score equivalent to about a 12.
Secondly, your child appears to have been given the Early Years version of the DAS (which was appropriate at age 5), which is quite different from the WISC. While this is the standard battery for five and six year-olds, in the case of suspected GT, I might have used the out-of-level norms (which are legitimate original norms) and administered the School Age battery instead, for its higher ceiling. The verbal tasks from that battery are also more directly comparable to those of the WISC.
Naming vocab is a picture vocabulary task, consisting only of nouns (obviously), whereas the WISC vocab is an oral task requiring verbal definitions of a range of words, including both concrete nouns and more abstract concepts.
Verbal comp is more like a task of following verbal directions, using toys and objects likely to be familiar to a first-world kindergartner. Many responses involve simple motor manipulations. Comp on the WISC is another pure verbal task drawing on knowledge of social conventions. A certain amount of life experience generally is necessary to score very high on this.
Re WISCIV VCI intersubtest scatter:
There are three verbal reasoning tasks (Similarities, Comprehension, Word Reasoning) listed here, and one verbal knowledge task (vocabulary). Similarities is a task of verbal concept formation--take two words and identify their commonality or category (e.g., three and four are both numbers). For comprehension, students are given a brief scenario, societal practice, idiom, etc., and asked to explain what it means, what expected behavior is, or the purpose of the convention. Much of this is learned from life, not books, and is strongly culturally-bound. Word reasoning is like progressive riddles. You try to guess a word (it may be an object or a concept) from a verbal clue. For most of the items, you can test your guess a couple of times, receiving additional clues after each guess.
It looks to me (totally blind, of course, since I didn't see it happen, and I don't know your DC!) like receiving feedback was extremely beneficial to your child's ability to demonstrate verbal reasoning skills. I also wonder if the low WISC Co score reflects the challenges in picking up cause-effect relationships in everyday/social situations that are often observed in individuals with ADHD/EF deficits. ASD is not the only profile that manifests as social skills weaknesses. ADHD does too, though for very different reasons.
