Some of these ScratchEd rubric resources might be useful: http://scratched.gse.harvard.edu/search/node/rubric%20type%3Aresource
And this rubric for assessing evolving fluency with computational practices, from our Computational Thinking site, might be of interest.
I'm curious to learn more about what you mean mean by "validated"? By whom and for what purposes?
How do I do that? What do you think? With discussions, you can share your questions, suggestions, and insights with others.