Children are first assessed to determine a group or Station. Strokes are then constructed systematically, with specific goals at each Station. Regular assessments are conducted and once elements of a station are mastered, swimmers are promoted to the next station. Lessons can become very skill oriented at this age. Preschool age children can learn to propel themselves independently in the water, can learn safety skills for themselves, learn to call for help for others and they can learn basic stroke skills in freestyle, backstroke, breaststroke and butterfly. They can learn to sustain themselves independently in the water for extended periods of time.