DTM.3:1 - Problem frame

Use this when a practice changes its participants, and those changes affect whether, what or how they pass it on—or when wider adoption changes the conditions under which participants can use it.

A learner becomes able to demonstrate a method only after practice. Growing adoption can overload shared teaching support. An installed standard changes which exchanges need conversion. A model that holds these conditions fixed can therefore predict the wrong continuation even if its separate local descriptions are reasonable.

The first result is a coupled account: which participant state changes which transmission or uptake event, and which population change feeds back to participants. It may be two connected ordinary sentences or a small mathematical model. Use MMP.18 for the general work of reconciling mathematical descriptions once these subject relations have been identified.

If participant change has no material effect on the receiving question over its horizon, retain the simpler transmission model.