Numerous studies document the value of worked examples in mathematics education and provide guidance regarding effective instructional design choices. The research described here draws on that body of work, research on learning from errors, and computer science education research, to study worked examples with errors for computer science education. I describe my prototype instructional designs using three programming languages and my two preliminary studies ' a quantitative study using worked examples in a college computer science class, and a qualitative study of a high school computing class. These innovations and experiments inform my doctoral research study.