PTJ's Pediatrics Special Issue focused on variability and how this concept is changing ideas about normal childhood development. In this discussion podcast, 3 of the authors from the Pediatrics Special Issue--Regina Harbourne, Beatrix Verijken, and Linda Fetters--join moderator James (Cole) Galloway to discuss variability, how children use variability to develop motor skills, and the role of variability in pediatric physical therapist practice. How can variability be used to identify healthy motor development, and how can it enhance intervention? How much variability is too much?