Here's another Scientific American blog article (Oct 4, 2011), "Drawing the line between science and pseudo-science," By Janet D. Stemwedel. Denimbius has offered some constructive comments:
While the example of creationism can be informative, perhaps the greater challenge to the problem of demarcation is the example of astrology, which the author mentions but doesn't directly address. Astrology is worthy of much more scientific scrutiny than it has received, especially in light of the findings of the late Michel Gauquelin. How have the scientific claims against astrology held up under Popper's criteria?
Astrology presents many "indications" or "significations," which due to the complexity of the subject and the insistence of astrologers on a holistic approach, are notoriously difficult to test.
To address this complexity, the 1985 double-blind experiment done by magician-scientist Shawn Carlson, set out to test what he called the "scientific hypothesis." Even a holistic approach to astrology, he suggested, could not be supported by the tests he designed. The tests in his experiment, published in NATURE [Dec. 1985, (318), 419-425] and by far the most frequently cited detailed claim against astrology, asked astrologers to match natal charts with psychological (CPI) profiles.
Although Carlson concluded his experiment with the assertion that the astrologers failed, recent peer-reviewed reassessments of the study have been critical of Carlson's analysis, pointing to numerous flaws, such as not following his own protocol, irrelevant grouping of results, and not reporting results that could have clarified a curious "statistical fluctuation" in the study.
As it turns out, when correctly assessed according to Carlson's own stated protocol and the normal evaluations of the social sciences, the data from the study actually supports the astrologers performance significantly better than chance. This critical evaluation might be the first well-documented case where the "scientific hypothesis" against astrology has been falsified according to Popper's criteria of demarcation.
This falsification of the scientific claim against astrology is a crucially interesting development for science. Clearly, the experiment needs a fair replication, which incorporates the improvements and safeguards offered by the critics. Until this happens, the claim that astrology is pseudoscience is seriously questionable. With the hypothesis for this widely cited experiment now broken, how does science explain the results?
Here are the links to the original Carlson article and some of its criticism: