They include human experience, observation of things in the natural world, comparison, contrast, classification, naming, trial and error, measurement, instruments like the telescope, scientific theories, and philosophies of science. One famous disagreement or debate in science at the time of Galileo was discussed briefly. And we considered at some length a great scientific discovery made possible by the application of the scientific method. How, then, should science be defined. But this is ordinary human experience, not science.
Science is a special kind of human experience, for there is an intent to learn more about the world.
There is an intention to answer a particular question, solve a particular problem, or meet a particular human need. That need may simply be the need of the scientist to satisfy his curiosity. Sometimes, too, serendipity enters into science, for a scientist may stumble into a great new discovery more or less by accident. Of course, he must be acute enough to recognize the significance of what he has tripped on. But, in any event, intent directs or channels human experience toward the end of increasing knowledge.