Threshold: ease of getting started with the material/kit and amount of prerequisite knowledge required.
Ceiling: potential complexity and applicability of the material/kit in the real world.
Self-guiding: level of instruction needed for using the material/kit.
Reversable: possibility of reverting design choices made with the material/kit.
Flexible: range of possible applications for the material/kit.
Robustness: how careful do you have to be with the material/kit.
Interoperable: can the material/kit be combined with other materials or kits.
