Information about the scientific method might inform readers about whether or not both evolutionary theory and intelligent design theory are science.
The foundation of science, the scientific method, starts with a statement that predicts an outcome (a hypothesis). Evolutionary theory might posit: “Changes in organisms result from an evolutionary process.” Intelligent design theory might posit: “Differences among organisms result from intelligent design.”
These hypotheses are tested using data that can be obtained by one of the following methods: 1) conducting an experiment or 2) observing new, naturally occurring data. Each method requires the collection of data with clear descriptions of the methodology, so that others can duplicate the research.
If the data support the hypothesis, the research is accepted as supporting the underlying theory. If not, doubt is cast on the theory. A key point is that the data must have the potential for being either consistent or inconsistent with the scientific hypothesis.
Both consistent and inconsistent data are possible for evolutionary theory, but examples of inconsistent data have not been described for intelligent design theory. Thus, evolutionary theory is scientific, but intelligent design theory is not.