11. The teaching aid of claim 10 wherein said diagram also comprises: presentation of said indicium in a manner that said indicium may be unambiguously identified within said diagram.
10. The teaching device of claim 9 wherein said indicium consists of: a graphically simple form, whereby said indicium remains individually identifiable by an unaided human eye at a viewing distance of 2.0 feet when said indicium is displayed with a maximum dimension of 0.2 inch.