Matching Pairs Concrete Operational StageOnline version This crossword puzzle is over key terminology related to Piaget's concrete operational stage. by Jennifer Paris 1 decentration 2 reversibility 3 identity 4 conservation 5 seriation 6 classification understanding that changes in one quality can be compensated for by changes in another quality arranging items along a quantitative dimension in a methodical way considering changes in more than one dimension understanding that objects have qualities that do not change even if the object is altered in some way. organizing objects by a variety of characteristics (size, color, shape, etc.) understanding that things that have been changed can be returned to their original state