What is the difference between operational and historical science?

Science in and of itself means “knowledge” and knowledge can be attained through two types of sciences: observational and historical.

Source: Answers in Genesis

Operational science is the broad field of science where experiments are performed and results are observed.  In this field, which includes chemistry, physics, hydraulics, engineering, modern technology, etc., experiments can be done to test a hypothesis, and the experiment can be repeated to measure validity and reliability.  This is the type of science that has given us computers, cell phones, televisions, and put men on the moon. 

Source: Answers in Genesis

Historical science includes the fields of archaeology and paleontology, to name a few.  These scientists “dig up the past” and come to conclusions based on interpretations of the evidence.  The interpretations are based on the scientist’s worldview and therefore are subjective.  Various forms of radiometric dating can be performed on the artifacts to determine how old they are, but these dating methods are based on assumptions

Both the Theory of Evolution and Creationism are historical sciences because all things studied have happened in the past.  The evidence use to support evolution is the same evidence used to support Creation but the differences depend on the worldview-based interpretations of the evidence.  Both have reasonable conclusions, but only one can be correct since they are complete opposites.