The standard conceptual approach usually entails specification of a technical relationship in the form of production functions, whereby an institution (such as a primary school) is seen as analogous to a firm, transforming inputs into outputs through a production process.

Typical inputs in the education production function at the primary level include government expenditures on teaching and the learning atmosphere, especially where the major output is defined in terms of pupils’ numeracy and literacy.

Certain primary educational practitioners have argued that where the relationship exists and can be quantified, policy can be constructed to maximize a preferred conceptual outcome. Indeed, considerable empirical research in this area has focused on identifying this technical relationship.

Nonetheless, the overwhelming literature on the subject of primary education points to the failure of education production functions to identify the purported/perceived relationship between key policy variables (such as resource spending) and educational achievement.

Two explanations for the failure of education production functions have been proposed.

These include the validity of the educational production function framework itself and the possibility of econometric misspecification; and the possibility that public policy may not have a measurable impact on educational outcome.

For example, some contended that innate ability combined with socio-economic background, may be more important in the educational production process.

Others have sought to define various dimensions of quality education. For example, a study conducted by the World Bank using a comprehensive review of research, identified five principal contributors to primary education effectiveness.

These include; curriculum; learning materials; instructional time; classroom teaching; and students’ learning ability.

Moreover, despite agreement in educational circles that hardware factors are perceived as being key determinants of education outcomes, some ambiguity in the importance of this factor exists. This may be partly explained by evidence suggesting that the quality of facilities may be more important in disadvantaged settings.

The role of teachers is generally accepted as crucial to learning outcomes. In most countries, developing and industrialized, teacher salaries account for half to three-quarters of education expenditures, rising as high as 90% in some African countries. Given the magnitude of this investment, it is important to know if it affects students’ learning outcomes.

Beyond that, most studies agree that time spent on teaching is an important condition for learning. Another characteristic of high-quality schools is assignment and correction of homework.

At the international level, debate continues about the relevance of class size. Others, however, claim that gains in educational quality will be realized by reducing class size, particularly in the early grades.

Whatever the results of these studies, which predominantly consider industrialized countries, a negative effect of student numbers might be expected in Africa where the average class size in primary schools is two to three times that in Europe or the United States.

Finally, children’s personal characteristics and background affect their persistence and attainment. These variables include the child’s health and nutritional status, gender and age, and parents’ or caregivers’ attitudes and experience with school. Prior schooling such as early childhood/pre-school programs will shape the child’s response to school.

Even so, developing countries are spending heavily on inputs, based on the perception that they improve learning. Hence, more research that employs different methodologies and datasets is needed to try to establish which inputs have a positive influence on learning outcomes.