In our therapy times, we had only one "communication partner." It would be the therapist during Woodjie's designated times during the week, or I would "reinforce" the PECs he would use. He can now pick the item or activity he wants out of several choices and request it using the picture. His therapists and I have mixed pictures and their order on his book in an attempt to discern whether he understands what he is asking for. Sometimes, he'll pick up a picture, pause with that "wait a minute" look on his face, put the picture back, and get the picture of the thing he really wanted the most.