The scientific definition of a theory is different from the general definition of a theory. In science you have four levels of ideas:
2) a hypothesis -- something you think you know how to prove but you haven't tested it yet. If your test works it becomes:
3) a theory -- something that has been proven in at least one test, but needs to be tested more to make sure the first test wasn't just a special case. If the theory survives lots of tests it becomes:
4) a law -- something people are so sure of they no longer bother to test it anymore. More precisely, a scientific law is something which has survived so many tests that contradictory data only modifies it or presents a special case.
For the next several weeks (or months) the tiny scientist will dilligently test this theory every chance she gets. Will things always fall down if you drop them? Does the direction and amount of force applied make a difference? Does the material composition make a difference? What about temperature? Does it matter if it went into your mouth first? Eventually she will assemble enough data to assure herself that things really will fall down if you drop them and stop the experiments. At that point she will have reached #4 and have a scientific law. It will have a broad enough base of data to cover any special cases, such as balloons. (Baby Brighteyes saw her first helium balloon while working her way through these experiments and screamed all day long.)
Yes, evolution is a theory. It has got to #3 in the scientific method. That's pretty good work in science. It's almost across the finish line! BUT intelligent design is still on #1. It isn't even in the race yet, and it won't be until it can be tested. It can't compete with anything that has survived even a single test. Until someone can come up with a test for it and test it out, it doesn't belong in the science lab.
If ID ever makes it to #3 in the scientific process list and becomes a scientific theory, it will certainly deserve inclusion in science books. It'll have to offer up a lot of concrete proof first. But no idea that's just on #1 passes muster.An idea gets to #4, scientific law, when the body of evidence for it is so great that evidence against it can't disprove it, but only modify it or point to a special case. Most scientists believe evolution has reached this point in recent years, especially after the de-coding of the human genome. It will certainly be called a law within a generation; but generally scientists are inherently conservative about adopting sweeping statements, as countless inter-science squabbles point out.