Collaborative Sketching, also known as C-Sketch or 5-1-3 G, is a method for concept generation in which several designers each sketch a design concept then pass their sketch to another designer to modify. Developed by Shah, collaborative sketching originated as a modification to Method 6-3-5. A key difference between collaborative sketching and Method 6-3-5 is that designers only work on one design at a time, whereas in Method 6-3-5, designers work on three designs concurrently.
Collaborative sketching has two basic variables: the number n of designers in the loop and the time t allocated for each iteration i. The number of iterations equals the number of designers. Therefore, a design team using C-Sketch will produce n designs. The two constraints in this method are (1) sketching is the only mode of communication between designers and (2) a designer cannot fully erase the sketch of another designer.
The basic protocol for C-Sketch is the following:
- The design team reviews the design objectives and chooses a facilitator to keep track of iteration time.
- The facilitator begins the first design iteration and each designer sketches a concept to meet the design objectives. This is the first design iteration.
- After t minutes are up, the facilitator instructs the designers to pass their sketch to the left or right. Designer j passes their sketch to designer j + 1, and designer n passes their sketch to designer 1.
- Each designer then adds, subtracts, or otherwise modifies the sketch passed to them for t minutes. This is the second design iteration.
- Steps 3 and 4 are repeated for n – 2 more iterations.