The arithmetic tie effect is mainly encoding-based.

Arithmetic tie problems like 6 + 6 or 7 x 7 can be solved much faster than non-ties. The present article contrasts two possible explanations for the tie effect, faster encoding of tie problems vs. faster access to arithmetic facts. For that purpose homogeneous (3 + 3, four x four) and heterogeneous (3 + three, four x 4) addition and multiplication problems had to be solved. For all participants the tie effect vanished with heterogeneous addition problems and for seven out of eight subjects the effect disappeared with heterogeneous multiplication problems. It is concluded that the tie effect is mainly encoding-based.