A new OECD study was published yesterday, examining what teachers know about teaching. This report does not provide “the answer” to what constitutes good teaching, but attempts, for the first time on a larger scale, to measure what teachers actually know about teaching and more. You will likely read little about it in the media, as only a few countries participated in this first round, but it is certainly fascinating.
The OECD has added a separate module to TALIS (their international teacher survey) for the first time: the Teacher Knowledge Survey (TKS). In this survey, teachers in lower secondary education (roughly our first stage) were asked not only questions about their work but also a test of general pedagogical knowledge. So, no subject matter, but topics such as instruction, learning, and evaluation. In total, it involved approximately 20,000 teachers from more than 2,000 schools. The eight participating countries were Chile, Croatia, Morocco, Poland, Portugal, Saudi Arabia, South Africa, and the United States.
It is also good to immediately put the brakes on how you read this: as always with such international comparisons, this is not a causal study. It shows associations, not causes.
What do teachers need to know?
What does the OECD actually mean by what teachers need to know and be able to do? They focus on what they call “general pedagogical knowledge.” In short: knowledge about how to design and manage learning environments, independent of the subject.
They break this down into three domains: instruction, learning, and evaluation. Teachers with a strong foundation here can better judge which strategies work. They understand how students learn—think motivation, metacognition, and development. And they make more meaningful use of assessment data.
At the highest level, this goes further. These teachers don’t just know strategies. They compare them, adapt them, and evaluate them. They understand the difference between formative and summative assessment. And they can interpret learning data. And they adjust instruction based on what students actually show.
This may sound abstract, but the core is familiar. Good teachers don’t just “deliver” lessons. They continuously adapt their approach based on what happens in the classroom. One caveat, though: this study mainly measures what teachers know about teaching, not what they actually do in practice.
The results?
And then the results. They are both interesting and typical of OECD reports: they confirm a number of intuitions, but with nuance.
A striking first point is that there is a fairly clear correlation between teachers’ average pedagogical knowledge in a country and students’ performance on PISA. Countries where teachers score higher on this knowledge also have better student results on average. But – I will repeat it anyway – that remains a correlation. You cannot draw causal conclusions from this.
What becomes more concrete are the differences in classroom practice. Teachers with greater pedagogical knowledge report spending more time on effective teaching and less time on maintaining order. They adapt their instruction to students more often, build up difficulty gradually, and appear to be more selective in how they use exercises.
In addition, these teachers report less stress. That is perhaps the most interesting insight: knowledge seems to be linked not only to better outcomes, but also to how feasible the profession remains for teachers themselves.
If you look at the countries, you see quite large differences. Portugal scores the highest on average, while countries like Morocco and Saudi Arabia rank lower. But at least as important: the differences within countries are often greater than between countries. In other words, the dispersion among teachers within a single system is enormous. The best-scoring teachers are not evenly distributed across schools, so students do not have the same chance of ending up with a strong teacher everywhere.
Conclusion
What this report primarily does is make visible something that often remains implicit. We have been saying for years, in fact for decades, that teachers are important. This report attempts to concretise that: what, then, makes them important? The OECD’s answer is quite clear: not only subject knowledge, but also a solid, explicit knowledge base about how learning and teaching can work.
At the same time, we must be careful not to read this as: “more pedagogical theory = automatically better education.” The report itself is too cautious for that. It shows connections, not recipes. But it does take an interesting step. If we take seriously that teaching is a knowledge-based profession, then we must also look more seriously at exactly what knowledge is associated with it – and how it is developed.