Observe carefully and develop preliminary ideas. Develop a formal theory, with testable prediction.

(a) Observe carefully and develop preliminary ideas. (b) Develop a formal theory, with testable predictions, that is consistent with all current relevant and reliable empirical evidence. The predictions need not be quantitative, but quantitative predictions are preferred where possible because they are more susceptible to falsification. (c) Test the predictions of the new theory against new observations in situations where the new and old theories make different predictions. Reject whichever theory fails the test, once the outcome is clear (so that observational errors, for example, cannot be driving the result). (d) Repeat steps (b) and (c) forever