Knowledge in the science curriculum

It is great to see that the curriculum is well and truly back on the education agenda in England. This is taking place at the same time that many teachers are re-affirming the importance of domain-specific knowledge and its crucial role in problem solving and expertise.

The knowledge produced by science: substantive knowledge

So, what knowledge should the science curriculum contain? Substantive knowledge (Schwab, 1964), that is, the knowledge produced by science involves concepts which form the underpinning structure of the subject e.g. respiration, evolution and the idea of a force. The list of substantive knowledge for science is, well, substantial, and beyond the scope of this short note, but probably should aim to create big idea thinking in the fundamental areas of biology, chemistry and physics. Students need to frequently practise retrieving and using the knowledge that builds these concepts, or else it gets forgotten.

Knowledge must be carefully sequenced in the curriculum over time. Because of the hierarchical nature of scientific knowledge, starting with the underpinning ideas and moving to the more complex is helpful, both within a lesson and wider curriculum. For example, it doesn’t make sense to learn about ions until you understand substances, atomic structure and charge. Sequencing knowledge gets more complex when you think about ordering seemingly separate but related ideas – for example, should we teach particles before cells or cells before particles and does it even matter?!

Substantive knowledge connected to more substantive knowledge creates understanding. Relate this knowledge to what you already know and you will create meaning (or misconceptions!) – the Holy Grail. This means that related prior knowledge must be re-visited in the curriculum before introducing new ideas and misconceptions should be actively surfaced and explored. I find it helpful here to imagine a digger arm, reaching back over the curriculum and scooping forward all relevant ideas that should have been learned to date. This scoop, along with your students’ various experiences and ideas, should then be the starting point for teaching. But all this re-visiting takes time and so a big part of curriculum design is about deciding what not to teach (see below).

And then there are important decisions to be made about assessment, because not all substantive knowledge is equally important. Particle model, for example, should be assessed in preference to sublimation. Why? Because the particle model is a gateway to understanding many more concepts (e.g.Yr8 conduction/convection, Yr9 osmosis, Yr10 rates of reaction) and so must be understood. Sublimation, while interesting, is quite a peculiar idea that has little explanatory power beyond state changes to iodine and carbon dioxide. As a piece of information, then, ‘sublimation’ has limited usefulness when it comes to learning science and so may be a contender when deciding what not to teach.

How knowledge in science is produced, developed and accepted: disciplinary knowledge

Then there is the knowledge about the discipline. This is the knowledge scientists need so they can collect, understand and evaluate scientific evidence. This isn’t reduced to a single algorithmic scientific method, but rather reflects the many varied ways in which science and scientists work.

Teaching this disciplinary knowledge is hard as ideas of the discipline can often become lost when students struggle to simultaneously grasp substantive knowledge. At the same time, it’s difficult for students to identify control variables during an investigation into photosynthesis, if they don’t understand the reaction itself. Get this delicate balance right, between substantive and disciplinary knowledge, and science teaching and learning becomes a whole lot easier and more interesting. It also becomes more meaningful because, as students come to understand the ideas of science, they also learn where these ideas came from. For example, to know what a mammal is requires an understanding of biological classification.

A science curriculum can support this interplay between substantive and disciplinary knowledge by articulating exactly what aspect of the discipline are being taught and positioning these in a facilitating substantive context e.g. teaching the concept of control variables when teaching about plant growth.

Further reading
  1. Building a curriculum towards big ideas
  2. Big ideas
  3. Powerful ideas of science
  4. Knowledge in the curriculum
  5. Coherence in the curriculum
  6. Powerful knowledge