Does Instrumental Enrichment Work?

Summary Israeli and American research on IE was reviewed, indicating effect‐sizes over a two‐year intervention period on tests of crystallised intelligence and achievement of the order of three months of mental age (MA) only. A small‐scale study (NE= 10; NC=10) was set up in an ESN(M) school under optimum conditions to test the effect of IE on the additional parameters of Piagetian Operations and of Phase, the Feuerstein information‐processing model. Effect sizes of 1.22σ on Operations, and 1.07σ on Phase were reported, together with 0.76a on deficient cognitive functions as tested by Feuerstein's Learning Potential Assessment Device (LPAD). In MA terms, these sizes corresponded to 20 months differential gain on Operations over a 20 month period, and 12 months differential gain on Phase over a 12#fr1/2> month pre to post‐test period. The gain on cognitive functions was accompanied by an increase in the zone of proximal development, as tested by LPA, of 1½ years. It was concluded that IE affects fluid intelligence initially, and that intervention studies were better tested on fresh learning embarked on after the intervention had ended than on standardised tests of achievement coterminous with the intervention. A strong plea was entered that the models underlying IE be absorbed into the public realm of intervention theory and curriculum development for remedial education.