The purpose of the present study was to extend previous research on reinforcer assessment by comparing effectiveness of stimuli identified by two preference procedures on teaching figure coloring to three children with disabilities in Turkey; and to find out what special education teachers think about social validation of the two preference assessment procedures. In Phase 1, preferences of three students with Down syndrome were identified by using two assessment procedures. In Phase 2, reinforcing effects of the most often selected stimuli both from the stimulus preference and paired-stimulus preference assessments were evaluated. In Phase 3, special education teachers' opinions about the two preference assessment procedures were determined. Results reveal that both preference assessment procedures were effective in identifying reinforcing stimuli for all three students with Down syndrome. Moreover, both procedures were found to be acceptable to some extent; however, results showed that the paired stimulus was more acceptable than the stimulus preference procedure. (Contains 3 tables and 2 figures.)