Unlike ADDIE, Rapid Prototyping gave instructional designers and developers the flexibility to jump around in the process and incorporate continuous improvements. Allen Interaction’s Successive Approximation Model (SAM) took rapid prototyping and added some welcome structure that allowed individuals and teams to iterate and change direction with a bit more order.
SAM actually comes in two flavours. SAM1 (for smaller, simpler projects) and SAM2 (for everything else).
SAM1 is a three stage cycle of Analyse, Design and Develop. You might be thinking, “That sounds a lot like ADDIE!”. The difference between SAM1 and ADDIE is that SAM1 is designed to be cycled three times. In the first cycle of the three stages you create a rapid prototype. Then you start the second cycle, Analysing the usage/feedback from that first prototype. As you continue with each cycle the product improves until after the third cycle the finished product emerges.
SAM2 is the heavyweight version for more complex projects. In the Preparation phase information is gathered and a kick off meeting gathers all stakeholders together to discuss goals and ideas for the project. Then the project moves through to the Iterative Design phase which, like SAM1, cycles rapidly three times, but this time through Design, leading to a Prototype which allows you the opportunity to Review and, cycle again! The end result is an advanced prototype called a Design Proof, a working (but not complete) version of the product that allows you to test out whether your design is likely to achieve your objectives and whether you have the systems and capability to produce it.
Next, the Iterative Development phase cycles, you guessed it, three times through Develop, Implement and Evaluate. The result should be a final product that, because it incorporates feedback from stakeholders throughout, avoids any wrong-turns and is far more likely to achieve its objectives.