PS 512 WEEK 2 On pages 108 110 of your text, Walker and Shea 1991 describe some of the unique ethical considerations that come into play when using single subject research. After an extensive review of the published literature, they compiled a list of ethical recommendations to follow when using single subject designs. Select two of these recommendations, and describe why you believe these are critical when working with special populations (e.g., those with developmental disabilities, mental retardation, or ADHD, etc.). How do these recommendations connect to the social and empirical validity of a target behavior