Explain why intelligent design is not a testable theory?

Creationism, intelligent design, and other claims of supernatural intervention in the origin of life or of species are not science because they are not testable by the methods of science. To be termed scientific, a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning. A scientific method consists of the collection of data through observation and experimentation, and the formulation and testing of hypotheses. Intelligent design relies on supernatural explanations that are often not testable nor reproducible. When testable 'experiments' are conducted their conclusions neither lend support or disprove anything with respect to intelligent design. They merely allow for a convenient segway to talk about creationism and other arguments which rely on faith.