So, for our second experiment, we needed data that would cause significant interference.
For this we selected two “quasi-contradictory” sets of mushrooms from the UCI mushroom
data base. Quasi-contradictory pairs of mushrooms are those that differ on no more than 3
(of 22) attributes with one member of each pair being poisonous, the other edible. There
were approximately 70 such pairs of closely paired edible/poisonous mushrooms in the UCI
database. We picked 20 mushrooms for the original training set and 20 “quasi-contradictory”
partners for the second set to be learned. The original set contained 17 edible mushrooms and
3 poisonous mushrooms. The second set of new mushrooms that closely resembled those in
the first set (the “contradictory data”) contained 17 poisonous and 3 edible mushrooms