Your comment and corrections are well-taken. For those of you new to this blog, Richard Garber brings expertise to the subject of public speaking, which I touched on in my blog, and has an informative blog, “Joyful Public Speaking,” to his credit. I recommend it.

One point where I may differ slightly, is that testifying ought not to be “impromptu,” in the sense of its meaning (“done without being planned, organized, or rehearsed”), but, as I have suggested, should be carefully prepared. That being said, the ability to express thoughts in a fluid, “free-form,” and coherent manner is much to be preferred to rehearsed, rigid, robotic testimony. What I would say is that, just as in the Olympics ice skating is judged with two scores, for “Technical Merit” and “Artistic Impression,” court testimony would have to have both sorts of preparation. The ability to speak extemporaneously in an “impromptu” manner would definitely be a huge plus in terms of artistic impression.

Thank you for your thoughtful contribution.

Yours,

Randy

Testifying is closer to an impromptu speaking situation like speaking up in a meeting, or talking to people in authority. Fears and phobias for those situations have been surveyed, and were reported in a magazine article by Ruscio et al. See this blog post for a discussion:
http://joyfulpublicspeaking.blogspot.com/2011/10/whats-difference-between-fear-and.html

Also, the percentages you cited were from the 1973 Bruskin survey, not the 1993 Bruskin-Goldring survey. I compared them here:
http://joyfulpublicspeaking.blogspot.com/2011/05/1993-survey-americas-number-one-fear.html

Richard