1. Preparation
2. Incubation
3. Illumination
4. Verification

Researcher Graham Wallis, many years ago, set down a description of what happens as people approach problems with the objective of coming up with creative solutions. He described his four-stage process as follows:

1. In the preparation stage, we define the problem, need, or desire, and gather any information the solution or response needs to account for, and set up criteria for verifying the solution's acceptability.

2. In the incubation stage, we step back from the problem and let our minds contemplate and work it through. Like preparation, incubation can last minutes, weeks, even years.

3. In the illumination stage, ideas arise from the mind to provide the basis of a creative response. These ideas can be pieces of the whole or the whole itself, i.e. seeing the entire concept or entity all at once. Unlike the other stages, illumination is often very brief, involving a tremendous rush of insights within a few minutes or hours.

4. In verification, the final stage, one carries out activities to demonstrate whether or not what emerged in illumination satisfies the need and the criteria defined in the preparation stage.

The first and last stages are left brain (Quadrant A and B) activities, whereas the second and third stages belong to the right brain (Quadrant D and C).

This model of the creative process has been placed on to Ned Herrmann's Four Quadrant model of the human brain.