Learning Envision / What Did Change, And How

Adoption runs at the speed teachers can absorb

The limiting factor has never been what is technically possible, and treating it as such produces forecasts that are wrong in a predictable direction.

Absorption capacity is a real and measurable constraint. A teacher has a fixed number of hours, an existing set of materials that work, a cohort arriving regardless of readiness, and reporting obligations that do not pause for innovation. Adopting something new means rebuilding materials, rehearsing unfamiliar practice in front of a group, and accepting a temporary decline in quality while competence is regained. That cost is paid by the individual, and the benefit is uncertain and delayed. Rational behaviour under those conditions is cautious adoption, and cautious adoption is exactly what the record shows.

This also explains why adoption clusters where the switching cost is lowest. Capabilities that slot into existing practice without requiring it to be redesigned spread quickly and quietly. Capabilities that require a different pedagogy, a different room, a different timetable or a different assessment regime spread slowly if at all, regardless of how much better they might be in principle. Technical merit is close to irrelevant to the rate of spread. Compatibility with what already exists is close to decisive, which is unwelcome news for anybody whose plan requires everything else to change first.

The design implication is straightforward and consistently ignored. If you want something adopted, reduce what it asks of the person adopting it, make its first use produce an immediate benefit to them rather than to a distant measure, and make partial adoption viable so that nobody has to commit everything at once. If you want to forecast adoption, count the hours it requires from people who do not have them. That single adjustment removes most of the optimism from most projections, and what remains is usually closer to what happens.