См.: этапы науки.
stages of a sciencestages of a science - - Scientific knowledge of a subject evolves over time. The stages of development are classification, correlation, and effect-cause-effect. Classification is the drive to answer the question: "What is this item?" The answer to the question is the development of a classification scheme and definitions of its classes. Correlation is the drive to answer the question: "How is this item related to other items?" The answer to the question is the statement of the relationship. Effect-cause-effect is the drive to answer the question: "Why is this item occurring?" The answer to this question provides a logical explanation of why the relationship exists between items.
Example: In the logistics function of an organization, manufacturing resource planning is viewed as the classification stage, just-in-time is viewed as the correlation stage; and theory of constraints is viewed as the effect-cause-effect stage of development.