The hypotheses and experiments lessons' strategy (HELS)

Introducing the Hypotheses and Experiments Lessons' Strategy (HELS) to primary science teachers in Egypt to evaluate its impact were reported in five years longitudinal study. The science teachers' pioneer group, who attended the first training program showed high interest in the strategy. The first teacher survey result showed that teachers recorded positive impacts of the (HELS) for students' conceptual change; however, there were difficulties that limited the frequency of its application. After attending the follow-up training program the trainees showed high level of understanding of the strategy. Thus, the second teacher survey result, showed that (HELS) proved high positive impacts on both science teachers and students in science knowledge, skills, and attitudes. The result of the class observation showed high level of class management of the (HELS), and more ability to discover students' misconception. The effective component of the introduced conceptual questions and experiments; beside the interactive discussion among students encouraged the conceptual change. Teachers showed high experimenting skills and changing from traditional teaching style to more practical teaching.