John -

I also ignored all the personal interactions ...

Yeah. That would be the novel, not the dissertation. But the beat goes on. And as much as I enjoyed the dissertation (and I did) and I am disappointed that one theme, advocated strenuously by one AS, was implicitly rejected without analysis, evidence, or comment. The "Disadvantages of Python" section includes both case sensitivity (with some equivocation) and zero based list indexing. There is also discussion of integer division with accepts in all respects the thinking that links the issue as a significant barrier to entry for beginners. My consistent position has been that these entry level barriers are demonstrably trivial next to the true and significant barriers inherent in the process of learning to program, as well expressed in Dethe's "Programming is hard" quote introducing Chapter 2. The particular "barriers" under analysis can as well be seen to represent aspects of a gentle introduction to the inherent uniqueness of the programming milieu, as distinct from the natural language or mathematical milieu. The adjustment to which is a necessity. Remove all trivial barriers, and we are only left with the significant ones. There is a wall, rather than a ramp leading over a wall. My Zen on the issues, and nothing more. But I feel strongly, and I think there is enough merit to require some evidence, counter-argument to reject out-of-hand in a study attempting some scientific grounding. Art