Correct answer:

(1) According to the realistic social relations and the needs of development. Specifically, different historical stages and different social systems need to formulate different educational purposes.

(2) According to the needs of social production and the development of science and technology. That is, the purpose of education should not only reflect the requirements of social relations and political economy, but also be restricted by the development of productive forces and science and technology.

(3) The cultural background of different countries will also restrict the formulation of educational goals.

In the final analysis, the scale and speed of education development are determined by the level and situation of productivity development. A certain education must adapt to a certain development of productive forces, which is the law that school education must follow in social development.