Our hope is that users will continually surprise themselves (and surprise us too) as they explore the space of possibilities.

These three components—low floors, high ceilings, and wide walls—have been adopted by the leading educational programming tools such as university-designed Agentsheets, Alice, Gamestar Mechanic, Scratch, and Star- Logo as weil as commercially developed tools such as Kodu.

The second principle was emphasized repeatedly, maybe because of its metaphoric quality: low threshold to enable easy entry for novices, high ceiling to enable experts to work on increasingly sophisticated projects, and wide walls to support a wide range of possible explorations.

To support and encourage this diversity, we explicitly include elements and features that can be used in many different ways. The design challenge is to develop features that are specific enough so that kids can quickly understand how to use them (low floor), but general enough so that kids can continue to find new ways to use them (wide walls).

The problem with systems that aim for a low threshold is that they usually are quite limited in what they can do, so users are either constrained, or else need to find “work-arounds” to achieve what they want. Tools with high ceilings tend to require significant training and effort to learn how to use. And wide walls means that there are very general primitives that users must learn how to combine.

One strategy to try to achieve all three is to explicitly include elements and features that can be used in many different ways. The design challenge is to be specific enough so that users can quickly understand how to use the features (low threshold), but general enough so that users can continue to find new ways to use them (wide walls). The tool should help users learn how to use the features, for example with mouse-overs, tool-tips, and a variety of examples, so users can make the transition necessary to understand the variety of possible uses.