Improvisation (also calle extemporization) is the practice of acting, singing, talking and reacting, of making and creating, in the moment and in response to the stimulus of one's immediate environment. This can result in the invention of new thought patterns, new practices, new structures or symbols, and/or new ways to act. This invention cycle occurs most effectively when the practitioner has a thorough intuitive and/or technical understanding of the necessary skills and concerns within the improvised domain.