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