Iris folding is a paper craft technique that involves folding strips of colored paper in such a way to form a design.The center of the design forms an iris â a shape reminiscent of the iris diaphragm of a camera lens.istory [edit]. Iris folding originated in Holland, where early craft people made their designs using patterned paper cut from the inside of envelopes. Today, crafters use any light weight paper, such as scrapbook paper, origami paper, wrapping paper, the inside of envelopes or pages of magazines. Ribbon is also used.
Extinction is the disappearance of a previously learned behavior when the behavior is not reinforced. In this lesson, learn more about extinction in operant conditioning and test your knowledge with a quiz.
1. the act of extinguishing. 2. the state of being extinguished or extinct. 3. the act or process of becoming extinct: the extinction of a species. 4. the reduction or loss of a conditioned response as a result of the absence or withdrawal of reinforcement.