The SECI Cycle

A teacher with twenty years of experience can read a class in thirty seconds. They cannot say how. The skill is real but not stated. This is tacit knowledge, and most professional knowledge is of this kind.

Tacit knowledge is hard to share. It does not fit in textbooks. It is hard to teach explicitly. The SECI cycle, developed by Ikujiro Nonaka and Hirotaka Takeuchi, is a method for converting tacit knowledge into something shareable, then back into tacit knowledge for new practitioners.

Tacit and explicit knowledge

Two kinds of knowledge sit at the centre of the cycle.

Tacit knowledge is what the practitioner knows but cannot easily say. It is built from experience. It includes intuitions, habits, instincts, and the kind of skill that gets called “feel”.

Explicit knowledge is what can be written down, said clearly, captured in a manual, or published in a textbook. It can be shared in standard form and read by anyone with the relevant background.

Most teaching knowledge starts tacit. Some of it becomes explicit. Most never does. The SECI cycle is a method for moving knowledge from one form to the other on purpose.

The four stages

The cycle has four stages. Each one is a particular kind of knowledge transformation.

Socialisation: tacit to tacit

The first stage is sharing tacit knowledge through shared experience. A new teacher watches an experienced colleague run a difficult class and absorbs something that no manual could convey. The experience itself is the medium.

In schools, socialisation happens during co-teaching, observation, mentoring, and informal conversation in the staff room. Knowledge moves from one practitioner to another without being stated, through proximity and shared work.

This stage is undervalued. A school that protects time for it produces faster development among its newer teachers than a school that does not.

Externalisation: tacit to explicit

The second stage is putting tacit knowledge into words, models, or images that others can read.

A teacher who has run successful group work for years tries to write down what makes their group work successful. The act of writing forces the teacher to articulate things they had only ever known by feel. Some of the writing comes out clearly. Some comes out vague. The vague parts often signal that the knowledge is more tacit than the teacher realised.

Externalisation is hard. It is also where useful generalisable knowledge gets created. A teacher who has externalised a method can share it with colleagues at a different school, who could not learn it any other way.

The work of externalisation often happens through dialogue. Talking through a method with a colleague who asks questions usually produces better articulation than writing alone.

Combination: explicit to explicit

The third stage is combining different pieces of explicit knowledge into something new.

A teacher who has externalised their group-work method reads a published article on cognitive load and combines the two into a richer method. The combination produces explicit knowledge that did not exist in either source alone.

This is the stage where formal study, reading, and structured discussion contribute most. A teacher who reads widely and combines what they read with what they have written down builds a richer conceptual base than one who does not.

Internalisation: explicit to tacit

The fourth stage is taking explicit knowledge and making it part of one’s own tacit knowledge through practice. Reading about a method is not enough. Using the method until it becomes second nature is internalisation.

A teacher reads about questioning techniques. They try them in class. At first, the techniques feel mechanical. After a term, they become natural. The explicit knowledge from the article has become tacit knowledge in the teacher’s practice.

Internalisation completes the cycle. The new tacit knowledge can then be socialised to other teachers, externalised in a new way, combined with further explicit knowledge, and so on. Each round of the cycle deepens the field’s collective knowledge.

How the reflective practitioner uses SECI

A reflective practitioner runs the cycle on themselves and with colleagues.

Knowledge is generated and internalised through experience. It does not require only direct experience, though. Through discussion with colleagues and through further experience within the context, the knowledge becomes clearer. The reflective practitioner, through dialogue and socialisation, begins to externalise the knowledge. It becomes explicit in the context of the work. Externalising the knowledge actually makes it clearer, and helps the practitioner understand it in greater depth and detail. As the practitioner thinks more about it and externalises through socialising, points of comparison and contrast with other knowledge start to appear.

This is the cycle in living form. The practitioner is doing all four stages, sometimes within the same week.

A worked example

A teacher has noticed that they handle a particular kind of disruption well. They are not sure how. Here is the cycle running on this knowledge.

Socialisation. A junior teacher watches the experienced teacher handle the disruption. The junior teacher absorbs something about timing, tone, and stance, without it being explicitly named.

Externalisation. The experienced teacher tries to write down what they did. The first draft is rough. They discuss it with the junior teacher, who asks “what did you notice in the second before you spoke?” The question forces the experienced teacher to articulate something that had been pure feel.

Combination. The teacher reads an article about de-escalation in classrooms. They combine what they have just externalised with the article’s framework. The combination produces a document that is more useful than either source alone.

Internalisation. The junior teacher uses the document in their own classroom for a term. At first, the technique feels mechanical. By the end of the term, it is natural.

A small piece of tacit knowledge has now spread from one teacher to another, become more explicit along the way, and been internalised in a new practice. This is the cycle at work.

Flashcard

What are the four stages of the SECI cycle?

Tap to reveal

Answer

Socialisation, externalisation, combination, internalisation

Socialisation moves tacit knowledge to tacit through shared experience. Externalisation makes tacit knowledge explicit in words or models. Combination joins different pieces of explicit knowledge into something new. Internalisation turns explicit knowledge back into tacit through practice. Together they form a loop.

Why this matters as a method of inquiry

Most teaching knowledge is tacit. A method that only works on explicit knowledge misses most of the field. The SECI cycle is one of the few methods that handles both.

It is also a method that depends on relationships. Socialisation requires time near a more experienced teacher. Externalisation often requires a dialogue partner. Combination benefits from a wider professional network. Internalisation happens alone but is supported by colleagues who help the practitioner notice when they are stuck.

A school that runs the cycle well produces practitioners faster than a school that does not. A school where teachers work in isolation produces practitioners much more slowly, and with more wasted effort.

A practical use

A teacher can use the SECI cycle deliberately on a single piece of practice they want to develop. The four steps:

1. Spend time with someone who already does it well. Watch them. Co-teach if possible. (Socialisation.)
2. Try to write down what you noticed. Discuss the writing with the colleague to refine it. (Externalisation.)
3. Read about the area and combine the writing with what you read. Produce a single document that holds both. (Combination.)
4. Practise using the combined understanding for a term. Do not stop until it feels natural. (Internalisation.)

This is slow. It is also one of the most reliable ways to develop a real new skill, as opposed to a superficial one.