As Piaget long ago observed, most learning is simply assimilation to an existing schema. But some really requires a shift. Changing the representational infrastructure can truly change access to thoughts that are otherwise hard to think.

A few other projects stand out as opening up reformation of the representational underpinning for learning. Ones that stick in my mind are (in no particular order) Logo, SimCalc, Media Computation, NetLogo, Scratch, AgentSheets, Hypergami, Sewable Computing/Lilypad Arduinos, Line Museaus’ work on integrating modeling into biotech instruction, and my own two integrated Computational Thinking projects including ChemC. Most people will not have heard of any of these, not even Logo and Scratch, which have had the wider popularity.

I will discuss four elements to this lack of impact.