Scientific theory - Ask.com Encyclopedia
A body of descriptions of knowledge is usually only called a theory if it has fulfilled these criteria:
It makes falsifiable predictions with consistent accuracy across a broad area of scientific inquiry (such as mechanics).
It is well-supported by many independent strands of evidence, rather than a single foundation. This ensures that it is probably a good approximation, if not completely correct.
It is consistent with pre-existing theories and other experimental results. (Its predictions may differ slightly from pre-existing theories in cases where they are more accurate than before.)
It can be adapted and modified to account for new evidence as it is discovered, thus increasing its predictive capability over time.
It is among the most parsimonious explanations, sparing in proposed entities or explanations. (See Occam's razor. Since there is no generally accepted objective definition of parsimony, this is not a strict criterion, but some theories are much less economical than others.)
The first three criteria are the most important. Theories considered scientific meet at least most of the criteria, but ideally all of them. This is true of such established theories as special and general relativity, quantum mechanics, plate tectonics, evolution, etc.
