Johnson (1967) suggests that curriculum is a nonsystem whose instructional system input should result in curriculum-development systems output. In considering the relationship between curriculum and instruction, Johnson (1967) emphasized that curriculum specialists were in fact mainly proficient on how to organize and direct groups effectively to improve curriculum (p.127). This was achieved by applying HR principles, and curriculum specialists were concerned more with improving curriculum development than in improving the curriculum itself (Johnson, 1967). Curriculum is conventionally defined by these curriculum specialists as a planned learning experience, which does not clearly delineate curriculum from instruction- yet again negating the potential for any clear definition (Johnson, 1967).
From this, perhaps the best definition of curricula might be the fluid dance between teaching and learning with politics and economics; always with the ongoing changing needs of society and the future cutting in. Curriculum is meant to be molded and shaped into what is necessary for modern day learning needs. Because these needs are continually changing, the role and meaning of curricula shall inevitably follow in suit.
Johnson, M. (1967). Definitions and models in curriculum theory. Educational Theory, 17, 127–140. doi: 10.1111/j.1741-5446.1967.tb00295.x
Oliva, P., & Gordon, W. R. (2013). Developing the curriculum (8th ed.). Upper Saddle River, NJ: Pearson