Externalization is a process of converting tacit knowledge into explicit concepts through the use of abstractions, metaphors, analogies, or models. The externalization of tacit knowledge is the quintessential knowledge-creation activity and is most often seen during the concept creation phase of new product development. Externalization can also be triggered by dialogue or collective reflection. Returning to the Matsushita case, Tanaka could not specify in engineering terms the “twisting stretch” motion she had learned from the master baker. Nevertheless she was able to communicate this tacit knowledge to the engineers by creating the mental concept of “twisting stretch,” and by indicating the power and speed of the kneading propeller in order to imitate this motion. For example, Tanaka would say, “make the propeller move stronger,” or “move it faster,” and the engineers would make the necessary adjustments through trial-and-error.