http://home.earthlink.net/~bluesman1/improvisation.html
This website involves teachers sharing ideas and there is a heading for improvisation.
http://webster.stjohns.k12.fl.us/child_jazz.html
This site gives techniques on how to get kids to improvise.
http://www2.potsdam.edu/crane/campbemr/curriculum/mej_composing.html
Composing and improvising citations from Music Educators Journal.