Our intent has been to apply what we know about learning to creating science curriculum that will motivate students to want to learn and give them an opportunity to put what they are learning to work. Design is targeted to success in the real world. Design sets constraints and experiments with variables to solve authentic problems. There are measurable criteria for success. Design is interactive through artifacts.
Artifacts are paper representations, models, computer simulations and objects.
The process of design is based on people interacting with artifacts and with each other through artifacts, to develop the best product possible to meet the criteria. Design is iterative. That means that a model is developed, tested, and assessed over and over again, for success or failure of a product, related to certain key criteria that have been established in advance. Failure is as informative, often more so, than success. The process of design cycles through with refinements and improvements until designers are as satisfied as they can be that the product designed on paper or in models or simulations will meet the criteria when it is actually manufactured and in operation.