This stage is characterized by absence of activity or thinking about the problem. We can take rest or engage in other activities. Sometimes when we engaged in other work, this experience provides clue to the solution of the problem. For example Archimedes found the solution of the problem when he was taking his bath. Illumination: This experience of sudden appearance of the solution is known as inspiration or illumination. If occurs at anytime, even in dreaming. A solution may appear when it is least expected. This process gives the insight or Aha experience to the thinker. You know that how Archimedes came out of the bathroom by telling that Eureka, Eureka. This Eureka is the Aha experience which is also known as illumination.