• Emily Rose Seeber

Stuff Chemistry teachers know about teaching Chemistry

So the big question for today is...

"Is what Chemistry teachers know about teaching Chemistry, more than a sum of what Chemistry teachers know about Chemistry, plus what Chemistry teachers know about teaching?"


The answer really all comes down to what you think is entailed by the notion of Pedagogical Content Knowledge, or PCK. Basically PCK means the special knowledge that a teacher has that enables them to teach and explain 'science' to students.

There area number of different models out there, but I am going to focus on just two:

  • Schulman's model

  • Lee and Luft's model

The reason for this is that Schulman's is the original; it set the scene. So by exploring it, we can better understand why PCK has led to a huge explosion in research in teacher education. The Lee and Luft model was constructed by teacher during the research, so closely maps what teachers actually think, which is why I think it is a particularly helpful contemporary model. It's about what works, not about what seems concise and coherent.


For Schulman, PCK is all about the representations, analogies and explanations that science teachers use to 'translate' the real world of science and the science curriculum, into something that students have a chance of learning. He was trying to show in the late 1980s that science teaching was a profession in the same way as being a lawyer, or a doctor. You needed a knowledge base from university, and then a specific set of knowledge which was unique to the particular profession of teaching science.

Schulman split PCK into two main knowledge bases:

  • representations and instructional strategies, and

  • student learning and conceptions.

His idea is that on top of their knowledge about science, a teacher needs to have an idea about how to break down the content, and also knowledge about how students learn that content. For example, when teaching particle theory, a Chemistry teacher has a knowledge of a range of ways of helping students understand the behaviour of particles in each state, and also a knowledge of the various misconceptions that students might have, such as that particles get bigger when they are heated. The teacher is then able to adapt the planning to take account of the students learning, and select analogies and demonstrations which will tackle students' misconceptions and help them to understand the accepted model.

7 Knowledge Bases

Lee and Luft's research in 2008 delved more deeply into the PCK debate, with a study on experienced science teachers, in which they identified the areas of knowledge they felt that they drew upon in their teaching. I find these particularly helpful, as they were defined by practicing teachers, so as a teacher mentor, I can identify with the areas, and easily help my teachers categorise their own knowledge and see areas for development.

The 7 areas of PCK are:

  • knowledge of science

  • knowledge of goals

  • knowledge of students

  • knowledge of assessment

  • knowledge of teaching

  • knowledge of curriculum organisation

  • knowledge of resources

So, according to their research, each of these knowledge bases is context specific. So this means that although there are some elements of general pedagogy what all teachers should know, there are also aspects of pedagogy which are specific to teaching science, or Chemistry.

For example, how to organise students during a complex practical task, or how to model conceptual ideas about the structure of the atom. They suggest that this isn't just a combination of knowing how to do the practical, or about the atom, combined with general pedagogical skills, Chemistry teachers also need to know specific techniques and illustrations that are specific to teaching Chemistry.

So a few words about what makes these knowledge bases specific in Chemistry teaching?

Knowledge of science

This is not just about knowing lots of 'Chemistry', although that's clearly an important base of knowledge. This also includes a teacher's beliefs about what makes Chemistry a distinct subject from Physics or Biology (both as subject domains, but also as school subjects), and a teacher's beliefs about what makes science different to non-science disciplines. The literature calls a lot of this material 'nature of science', but I think that the nature of Chemistry is distinctive (I talk about this more in an article for TES).

Knowledge of goals

This is about knowing what we want students to be able to do as a result of their Chemistry teaching. Do we want them to be able to get A*s, or be able to design experiments, conduct a research project, or have a greater appreciation of the material world around them, like where colour comes from? With the exception of a grades focused approach, many of these are, or can be seen as, distinctive to Chemistry.

Knowledge of students

This is more than just knowing the students as generic tutors, but also knowing how they are likely to respond to what they are being taught in Chemistry. Which students will struggle with abstract concepts, or find manipulating apparatus tricky, or have prior misconceptions about the structure of the atom?

Knowledge of assessment

Again this is more than knowing the nature of the terminal assessment in Chemistry (how many papers, which topics are on them): this is also a deep knowledge about how to assess students depending on the learning you are trying to assess. How can you assess students understanding of the distillation of an aldehyde during a practical? Which questions should you ask? When should you use a hinge point question and what incorrect answers might you choose in a multiple choice?

Knowledge of teaching

This matches up well to Schulman's model of PCK as representations and instructional strategies. What is the knowledge base required to teach rates effectively? What models and diagrams would you use? How do you structure the lessons to build and scaffold understanding and link the macro and micro? This is clearly Chemistry specific to a large extent; the strategy you use is deeply linked to what the content actually is.

Knowledge of curriculum organisation

The curriculum is, again, intrinsically linked to the subject content. Knowing the Chemistry SOW inside out makes a huge difference to my teaching, but knowing the Physics SOW is significantly less helpful. I wouldn't have real knowledge of it, I'd look it up if I needed to know anything. The one I need in my knowledge is the Chemistry.

Knowledge of resources

This might be resources for using in lessons, negotiating Chemsheets, Knockhardy, Goalby, RSC Learn, TES, etc. But also includes knowing which colleagues in your department are the people to ask about new practicals, or planning, or museums, exhibitions, Olympiad, events at local universities, talks, etc., which we can use to enrich students' Chemistry education. Generic teaching resources are not that helpful; it's the subject specific stuff that makes a difference to our knowledge base.

Why should I care about PCK?

  • As teachers, reflecting on our planning using the knowledge bases helps us to plan lessons which draw on a wide variety of different areas, and ensure that we are not relying on one knowledge base, to avoid any weaknesses in other areas.

  • It can help with professional development; once areas are identified we can take on CPD which will actually enrich our knowledge bases, rather than building a tower on the already overloaded side of the knowledge boat.

  • When we are planning training for our staff, we need to take context into account as pedagogical knowledge transmitted to staff is significantly more valuable if it is contextual. Staff training sessions should be aimed at specific subjects or topics more regularly, for maximum impact.

So, back to the 'big question': "Is what Chemistry teachers know about teaching Chemistry, more than a sum of what Chemistry teachers know about Chemistry, plus what Chemistry teachers know about teaching?".

I think the answer is a resounding "yes"!

#professionaldevelopment #teachereducation #chemistry #science #philosophyofscience #PCK


© 2017 by Emily Rose Seeber.