Our tendency when working with children is to use "Direct Verbal" prompts. For children with WS, this is very distracting to what they are doing because it starts a conversation/connection. Children with WS are "hard wired" for conversation/connection. Therefore, they stop what they are doing to engage in that conversation, and what they were working on previously is forgotten. 

Using silent cues such as gestures or visual prompts is far more effective for building task endurance and independent work skills. Indirect prompts also help build problem solving and decrease learned helplessness.