The strongest single factor sits outside the training room

What the person's supervisor does in the weeks afterwards shapes the outcome more than most decisions a designer can make.

Of all the influences on whether a new practice survives, the behaviour of the immediate supervisor is consistently among the most powerful, and it is almost entirely outside the control of whoever built and delivered the training. A supervisor who knows what was covered, expects to see it, asks about it in the first week, and tolerates a slower first attempt creates conditions under which even mediocre training produces some change. A supervisor who does not know what was covered and never mentions it again creates conditions under which excellent training produces very little.

This is not principally about encouragement or motivation. It is about signal. In a busy workplace people allocate effort according to what is noticed. If nobody asks, the new practice is unmonitored, and unmonitored effort loses to monitored effort every time, not through cynicism but through ordinary triage. A single specific question, asked once, about how the new approach went on a particular job, does more work than any amount of post course communication from the training function, because it comes from the person whose attention actually organises the week.

The consequence for practice is that any serious attempt at transfer has to reach the supervisor, and most attempts do not. Supervisors are typically told that their staff member will be away on a date, and nothing else. They receive no summary of what was covered, no suggestion of what to look for, and no request to ask about it. Fixing that is not expensive: a short note, in plain language, listing two or three things the person will be trying, sent to the supervisor rather than the participant. It is one of the few interventions in this whole field that costs almost nothing and reliably moves the outcome.