Here is my clubs definition of "soloing" --- I thought that chartered AMA clubs would be similar.

www.flyingelectrons.com

Enter site
go to club documents (left column)
go to training program

(sorry, cant seem to put the page up directly)

I assumed that this was the standard definition of solo, barring minor differences. No one at my club is a pilot that doesnt complete this program, to the best of my knowledge, so it seems fairly comprehensive.

I do, however, understand that its possible to be on your best behavior while training, and then become a maniac in the sky, but it seems to me that a well constructed and established training method is the way to go.