Translucency of sign and concreteness of gloss in the manual sign learning of moderately/severely mentally retarded students.

The effects of high and low levels of manual sign translucency and referential concreteness on the manual sign learning of moderately/severely mentally retarded adolescents were investigated. High levels of translucency were shown to be a significant facilitator of sign learning and low levels of the variable inhibited learning. Concreteness did not significantly affect sign learning. Implications for the effects of the two variables on the sign learning of retarded students were discussed.