The impact of high- and low-preference stimuli on vocational and academic performances of youths with severe disabilities.

Pictorial and tangible paired-stimulus preference assessments were compared with 4 adolescents with developmental disabilities. In the tangible assessment, two stimuli were placed in front of the participant on each trial; in the pictorial assessment, two line drawings were placed in front of the participant on each trial. Approach responses were recorded for each assessment. The assessments generated similar preference hierarchies for all participants. Reinforcer assessments confirmed that response rates were higher when access to high-preference items was available than when low-preference items were available. Implications for assessing preferences and selecting items to be used in training programs are discussed.

Using pictures to assess reinforcers in individuals with developmental disabilities.

Tangible preference assessments were compared with pictorial preference assessments for 4 individuals with developmental disabilities. In the tangible assessment, on each trial two stimuli were selected and placed in front of the participant, who approached one. In the pictorial assessment, on each trial two line drawings were placed in front of the participant, who pointed to one. For both assessments, the percentage of opportunities each stimulus was approached or touched was calculated, and hierarchies of preferred items were developed. The two assessments yielded similar preference hierarchies for 3 of 4 participants. Reinforcer assessments using a simple free operant response confirmed that items identified as highly preferred on tangible and pictorial assessments functioned as reinforcers.