Two of these five types are fraction pairs with common components
(CC), while three types are pairs without common components
(WCC). Fraction pairs of CC-items have either the same
denominator and are therefore congruent (CC-CO) or the same
numerator and are therefore incongruent (CC-IC). In both cases, it is
sufficient to compare the non-equal parts in order to solve the
comparison problem. In contrast, for theWCC-items, the numerical
values of the fractions have to be considered. If each component of
one fraction is larger than the respective component of the other
fraction, the item can be congruent (WCC-CO) or incongruent
(WCC-IC). If the numerator of one fraction is larger than the
numerator of the other fraction and vice versa for the denominators,
the item is neutral (WCC-N), because comparison of
the components leads to contradictory results.