Kathleen Hayward is a professor emerita at the University of Missouri. Where she has researched life span motor development and taught courses in motor behaviour and development, sport psychology and biomechanics. Haywood is also the coauthor of four editions of Archery: Steps to Success and of Teaching Archery: Steps to Success, both published by Human Kinetics. Nancy Getchell is a professor at the University of Delaware. For nearly 30 years, Getchell has investigated developmental motor control and coordination in children. She is a research fellow of SHAPE American and has served as the chairperson of the Motor Development and Learning Academy.