Basic Concepts: Why the Usual Ways of Teaching Fall Short
Most instruction on a shop floor is some mix of telling and showing — each can work, and each has real limits when used alone.
Before learning the Job Instruction method, it helps to see where teaching fits among a supervisor's responsibilities, and then why the everyday ways people teach are unreliable. Most instruction on a shop floor is some mix of telling and showing. Each can work, and each has real limits when used alone.
By the end of this section, you should understand:
- how teaching fits among the five needs of a good supervisor, and that Job Instruction develops the skill of instructing,
- the four common teaching methods and what each one is,
- why each method, used by itself, is not enough,
- the classic demonstration TWI uses to make this obvious — the Fire Underwriter's Knot,
- what a reliable teaching method has to do instead.
1The five needs of a good supervisor
Job Instruction does not stand alone. It is one of the skills a supervisor needs to lead an area well. Experience across many industries points to five needs that every good supervisor must meet.
A good supervisor meets five needs: two kinds of knowledge, learned locally, and three skills, developed through practice. The three TWI "J" programs were each built to develop one of the skills — Job Instruction develops the skill of instructing.
What to notice: knowledge is specific to a plant and cannot be supplied by a course. The three skills can be taught — and that is exactly what Job Instruction, Job Methods, and Job Relations set out to do.
The first two are kinds of knowledge. The last three are skills. Knowledge tends to be specific to a job or a plant. The three skills can be developed through practice, and the three TWI "J" programs were built to develop them:
This guide is about the third need: skill in instructing. Few people are born with it. Like the other skills, it is acquired through conscious effort and constant practice.
2The four common teaching methods
Almost all instruction falls into four categories:
| Method | What it is |
|---|---|
| Telling | Explaining the job in words. |
| Showing | Demonstrating how the job is done. |
| Illustrating | Explaining with written or drawn material — charts, diagrams, blueprints, sketches. |
| Question & Answer | Asking questions that guide the learner toward the right understanding. |
By far the most common are telling and showing. Used together by a skilled instructor, they can be effective. The trouble is that each method, used alone, leaves predictable gaps — and most everyday instruction leans on one of them without the discipline to close those gaps.
3Why each method alone is not enough
Telling alone is not enough
When you describe a job only in words, three problems appear:
- Things sound more complicated than they are. Few of us pick exactly the right words to describe a process.
- Some actions are very hard to put into words at all.
- It is easy to tell more than a person can absorb in one sitting.
Thousands of workers are being told how to do things at this very moment. How many of them truly understand? Telling without showing is the real cause of many of the problems an area faces.
Showing alone is not enough
Showing has its own limits:
- Copying is not the same as understanding. A person can imitate your motions and still not know what they are doing.
- Many motions are difficult to copy, and the learner misses the finer points because they do not yet know what to look for.
- Even a perfect imitation cannot be carried further. The learner cannot easily translate what they saw into what they must now do.
Illustrating alone is not enough
Charts, diagrams, and sketches are valuable, and a good sketch on a scrap of paper has rescued many an explanation. But if the person you are illustrating for does not have technical knowledge equal to yours, they may simply miss the point the illustration is meant to make.
Question & Answer alone is not enough
Questioning is useful throughout instruction — to prepare the learner, to check understanding, and to help the learner think through the logic of the job. But it cannot carry the whole load by itself.
When you use questions, ask ones that begin with what, who, why, when, where, or how. These cannot be answered with a simple "yes" or "no," so they reveal what the learner actually understands.
4The Fire Underwriter's Knot demonstration
TWI makes the limits of telling and showing unmistakable with a simple job borrowed from the electrical trade of the 1940s: tying the Fire Underwriter's Knot. The demonstration is worth understanding because it captures the whole argument for the method.
Telling alone. The instructor keeps a length of cord out of sight and reads the steps of the knot aloud, in full detail — a dozen or more steps. Then the instructor hands a cord to a learner and asks them to tie it. The learner almost always struggles. The instructor's line is deliberate:
"The failure to tie the knot was not your fault. It was my poor instruction."
Showing alone. The instructor then ties the knot in silence while a learner watches, and hands over the cord. Even watching closely, most learners reverse the knot or lose the sequence. Showing, by itself, did not transfer the skill.
The demonstration lands the point that no amount of repetition fixes: telling alone and showing alone are not reliable. They may work sometimes, with some people, but they cannot be counted on.
The instructor reads a dozen-plus steps aloud, then hands over the cord. The learner almost always struggles — words alone cannot transfer the knot.
The instructor ties the knot in silence while the learner watches, then hands over the cord. Most learners reverse the knot or lose the sequence.
The knot demonstration shows learners failing under "telling alone" and "showing alone," setting up the need for a reliable combined method.
What to notice: the instructor takes the blame each time. That is the motto in action — if the worker hasn't learned, the instructor hasn't taught.
5What a reliable method must do
If telling, showing, illustrating, and questioning each fall short alone, the answer is not to abandon them. It is to combine them in a disciplined order that does what none of them does by itself.
A reliable teaching method must:
- present the work in small, ordered pieces a person can absorb,
- combine words with demonstration so meaning and motion arrive together,
- make the learner do the job, not just watch it,
- confirm understanding before the person is left on their own,
- give the same result every time it is properly applied.
A reliable method does not depend on the talent of the instructor or the quickness of the learner. Applied correctly, it works every time.
That is what the Job Instruction four-step method provides, and it is the subject of the next section.
Section summary
Teaching is one of the five needs of a good supervisor — and one of the three skills the TWI "J" programs were built to develop, with Job Instruction developing the skill of instructing. Most teaching is some mix of four methods — telling, showing, illustrating, and questioning. Each has value, and each is unreliable on its own. Telling makes work sound complicated and overloads the learner; showing produces imitation without understanding; illustrating fails when the learner lacks equal background; questioning cannot carry instruction by itself.
The Fire Underwriter's Knot demonstration makes these limits plain: learners fail under telling alone and under showing alone, no matter how many times the method is repeated. A reliable method must combine these approaches in a disciplined order — presenting the work in small pieces, joining words to demonstration, making the learner do the job, and confirming understanding — so that it works every time it is applied correctly. The next section presents that method: the four steps of Job Instruction.