Date of Graduation


Document Type


Degree Type



College of Physical Activity and Sport Sciences


Physical Education Teacher Education

Committee Chair

Andrew H. Hawkins.


Ecological Task Analysis (ETA; Davis & Burton, 1991) hypothesizes that movement change may emerge from dynamic interaction in given environmental conditions. In other words, task variability provides opportunities for the performer to choose skills suitable to his or her capabilities in order to achieve a task goal.;The purpose of the present study is to examine 4 year-old children's changes in throwing patterns and perceptual judgment as a function of task variation in specific throwing tasks. Each experiment identifies various task parameters (e.g., force, trajectory of throws) and attempts to adjust them to meet a task goal.;The modifications of tasks include changes in distance from targets, size of ball in relation to target size, and height of target in relation to eye-height level of children. The research designs for this study were alternating treatment design and simultaneous treatment design in single case study. Experiment 1 of the study measured the extent to which throwing patterns change in accordance with variations in height of target, examine observable throwing patterns and measure the changes in humerus angle toward trunk. Experiment 2 examined the perceptual judgment of four-year-old children in seeking strategic solutions relative to the physical dimensions of balls and hoops, in the context of goal-scoring tasks.;The four year-old children responded to changes in the height of a target in relation to their eye height level and demonstrated lifting up the humerus to create higher trajectory at a high target. The strategy with the upper arm action cannot be believed to be effective for achieving the goal. However, it might be one of the solutions for scoring at the hoops, something individuals with the immature throwing skill might do. The distinct patterns of individual participant's throws may present the empirical evidences that they might be capable of comprehending the interaction well among constraints as changing a task condition in the way the developmentalists in dynamical systems theory explain changes in movements.