Criteria for Scientific Theories
Any theory to be considered as science must meet these minimum requirements. It must be:
1. Internally consistent
2. Experimentally verifiable
3. Predictively useful
ID advocates have failed to produce such a theory on all counts.
1. IDers are all over the place when it comes to agreeing how much evolutionary theory (if any) they are willing to accept before ID "kicks in." The irreducible complexity (IC) formulation, which is to provide an "objective" measure supporting their propositions, contains an "R" factor, or "rejection region" which allows for the dismissal of signs of complexity which are "obviously" a result of natural causes, not ID. And who determines what falls into this rejection region? Why it's the ID investigator himself! As more natural causes fill in these "gaps," and enter the rejection region, ID "theory" eventually evaporates into thin air.
2. With no cogent theory, there are no hypotheses available to test. No research can be done. No results can obtain. Colloquially speaking, there is no "there" there.
3. Saying "God did it" whenever we find a gap in our knowledge provides us with no useful way to proceed. Information theory tells us that the information content of a message is related to its unpredictability. If "God did it" is the answer every time, then the information value is zero.
Since ID does not meet these three criteria, it is not science and cannot be presented in a public school science class.