Science and Pseudo-Science

What is the difference between genuine science and pseudo-science? One suggestion is falsifiability. Those theories that can be falsified, i.e. which make predictions which can be tested and which therefore could be shown to be false, are scientific. Those that do not, are not.

This criterion is met by all of those theories that are traditionally taken to be scientific. The natural sciences, for example--biology, chemistry, and physics--all make predictions that can be tested.

The criterion also rules out many of those theories that do not seem to be scientific. The claims of astrology, and arguably of religion, cannot be empirically tested, and so astrology and theology are not sciences, by this criterion.