We are in the process of creating a classification structure of health concepts (symptoms) that will be used within the user interface of a children's symptom management system called PedsCHOICE. Through studies conducted during the development process, we have learned that there are many factors that influence the structure of the symptom categorization that go beyond the user's cognition and ways of thinking. Restraints such as emotional reactions/acknowledging illness, children's development of motor skills, in addition to children's conceptualizations of categories all affect how a health application should present content.