Pseudoscience masquerades as science, usually to promote some commercial scam or to promote religious beliefs for which there is not, nor ever will be, supportive evidence.
The subject matter of pseudoscientific claims ranges from astrology and the occult to anti-science, religiously motivated falsehoods.
By my definition, to lay claim to being legitimately within the sphere of scientific knowledge, the claim must:
A) For physical evidence that is not subject to experimental verification: exist as tangible evidence that is uncovered under controlled conditions and is interpreted in accordance with current knowledge – for example, a paleontological fossil, an anthropological artefact, an archeological find. That same fossil, artefact, or ruin cannot be considered to fall within the realm of science when it has been unearthed without any attention to its context, or experimental verification of its associations and age.
B) For experimentally generated empirical data: the scientific method can be applied to physical data that is experimentally testable, repeatable, and, ideally, falsifiable. The experimental data must be logically interpreted in accordance with current knowledge.
Talking or writing about science is not science. Criticizing or critiquing science is not science. Elaborating mumbo-jumbo about supposed medical treatments without clinical testing is not science. Concocting falsehoods designed to protect unjustified belief in disproved Special Creation is definitely not science.
In order to ignorantly support illogical, indoctrinated religious mythology, creationists deny scientific knowledge, attack a straw man version of science, and falsify science as lie-oramas in the Fiction Lie-See-Um, or tout Misleading Pseudoscience for Dummies on junk tanks. " Creationism has been discredited, however, by indisputable physical evidence – carbon dating, for example."[SW]
External : Science Week editorials : Creationism vs. Sanity : SCIENCE POLICY: ON THE TEACHING OF PSEUDOSCIENCE :