Decreasing errors in reading-related matching to sample using a delayed-sample procedure.

Two men with intellectual disabilities initially demonstrated intermediate accuracy in two-choice matching-to-sample (MTS) procedures. A printed-letter identity MTS procedure was used with 1 participant, and a spoken-to-printed-word MTS procedure was used with the other participant. Errors decreased substantially under a delayed-sample procedure, in which the choice stimuli were presented first and the sample was presented only after 5 s without a response to the choice stimuli.