Presentation by Emily Kwan, BCBA This presentation illustrated the process of teaching a 6-year-old boy to respond to social questions through picture exchange communication system (PECS). In addition, it illustrated the use of PECS at an advanced level. In this presentation, Emily used videos to demonstrate how the boy organized his PECS book of 300 pictures, use action words to construct grammatically correct sentence, request multiple items at a time, uses attribute to dif