[penteract]

Thanks for the explanation and the link.

So the goal is to find real numbers f_I, f_A, ...f_ABC such that

result = f_I + f_A*v_A + f_B*v_B + f_AB*v_A*v_B + ... + f_ABC*v_A*v_B*v_C

where v_A is 1 or -1 depending on whether A is present or absent in the experiment. f_AB is being abbreviated to AB, which is causing some confusion, since when heading a column, AB means v_A*v_B. The article should say that we can't tell the difference between the effect associated with B and the effect associated the 3-way interaction (for this definition of the effect associated with the 3-way interaction).