Hoping this will help rather than just belabor the obvious...
In the original document, in the notation kC2 the
k and 2 are written small, like subscripts.
Another form of this notation is C(k,2).
C(k,2) denotes the number of combinations of
k items taken 2 at a time. Let's say there are k=5
subjects, named A, B, C, D, E. From this set of
5 items there are C(5,2) distinct 2-member sets
of items taken from this 5-member set {A,B,C,D,E}.
C(5,2) = 10, and these 10 two-member sets (pairs) are
{A,B}, {A,C}, {A,D}, {A,E}, {B,C},
{B,D}, {B,E}, {C,D}, {C,E}, {D,E}.
The notation {B,E} means a two-member set,
exactly the same set as denoted by {E,B}.
If the order of the elements makes a difference,
then we are dealing not with sets but with
ordered pairs, which are denoted with parentheses.
The ordered pair (E,B) is different from
the ordered pair (B,E).
So from each pair {X,Y} we can derive two
distinct ordered pairs, namely, (X,Y) and (Y,X).
http://www.itl.nist.gov/div898/handbook/prc/section4/prc472.htm and
http://en.wikipedia.org/wiki/Scheff%C3%A9%27s_method
give an explanation of Scheffe's method but require a lot of
background information to follow.
-- Mark Spahn (West Seneca, NY)