Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and settlement. The pattern has been used by historians to document how innovations happened. The authors used it in addition to help students learn to spot modern "messes" and use them as springboards to generate innovations of their own.