Cambodia’s primary education curriculum allocates a relatively high proportion of time to literacy and numeracy, indicating that curriculum design itself is not the main barrier to student learning. However, actual instruction time is significantly lower than the prescribed 728 hours due to instruction time loss, which some studies estimate could be as high as a quarter of intended instructional time. Reliable data on instruction time loss is limited, but it is a key challenge affecting student outcomes.
Global evidence shows a positive but weak relationship between instruction time and student test scores. While more instruction time is generally associated with slightly better literacy and numeracy performance, there are many exceptions. Some countries with high instruction hours perform poorly on tests, while some top performers have below-average annual instruction hours. Experience from countries that adopted full-day schooling indicates that increasing instruction time does not guarantee improved test scores. Gains are often modest, reforms are expensive due to increased teacher wage costs, and implementation can take more than a decade.
Different approaches to increasing instruction time vary in cost-efficiency. Full-day schooling, which extends the school day into afternoons, is costly because it requires constructing additional classrooms. More cost-effective options include split-day schedules or extending the school year, which do not require significant capital investment. The most efficient approach is addressing instruction time loss by reducing teacher absenteeism and unofficial school closures. Teacher norms and HR regulations play a crucial role in determining the affordability and feasibility of such reforms.
Recommendations emphasize that instruction time reforms should first address time loss. A detailed study is needed to quantify time lost and identify causes such as absenteeism and school closures, which should then be combined with measures to increase lesson time. Given the high cost and uncertain impact of reforms, a cautious, iterative, and long-term approach is advised, with pilot programs tested before large-scale implementation.
Revisions and strict enforcement of teacher HR regulations are also recommended. Clear curriculum guidelines, teaching norms, and compliance measures should ensure that teachers meet minimum in-class and out-of-class working hours while reducing secondary job commitments. Finally, continued investment in the quality and effectiveness of instruction remains critical. Promoting early-grade reading, numeracy, and teaching-at-the-right-level strategies can significantly enhance student learning outcomes alongside any increase in instruction time.
