This term (and
paradigm) comes from the
historian of
science Thomas Kuhn. A paradigm is the set of unquestioned ideas
scientists share when doing
normal science. A paradigm shift is when a paradigm fails radically to explain the data, and instead of changing it a bit, science has to make up something new. This is also known as
revolutionary science, or a
scientific revolution.
Sample paradigms and paradigm shifts.
This term is abused and used out of context all the time.