On my main astrology blog a reader pointed out OK Cupid's post about attraction and a section written on zodiac signs. 

http://blog.okcupid.com/index.php/how-races-and-religions-match-in-online-dating/

with the comment "It seems like astrological sign has no impact on personality."

And OK Cupid's official spokes people have a stronger message:

"Since he’s a Pisces and I’m a Virgo, Chris and I of course think the Zodiac is total bullshit, and it was very gratifying to have the data bear this out. Here are the grouped match percentages for a random pool of 500,000 users. Astrological sign has no effect whatsoever on how compatible two people are." 

Actually, the OK Cupid data set shows nothing of the kind.

Even with ignoring the obvious bias of the writers of the post, the OK Cupid conclusions are illustrative of examples of fallacious thinking about relationships in general and astrology in particular.

OK Cupid’s assumption that people are attracted to people who share likes and dislikes. This is one theory about attraction, but it is only a theory. Years of research have failed to cement this as the primary reason why people are attracted to each other. Research literature suggests that biological responses primarily fuels attraction, with cues such as smell and body features carrying the lead. As a relationship astrologer who has talked with hundreds of clients about the success or failure of their relationships I can tell you that similarities in personality fuel attraction far less than people generally assume. And as a more wiser astrologer than I pointed out, the general assumptions of people does not make for good evidence.  So the idea that certain zodiac sun signs get along better than others and thus fuels attraction is an example of the fallacious argument called Hasty Generalization.

Actually the assumption that certain Sun signs get along better with others is a misunderstanding of principles in astrology that illustrate why certain zodiac signs share or don’t share certain traits. In addition Sun signs alone do not compatibility make. All the other planets in the solar system have something to say about the complexity that makes up human relationships.

This Hasty Generalization then feeds into another type of fallacious argument that because the first theory is proved “wrong” then astrology has no impact on personality. This fallacious argument is called the Straw Man argument.

People are absolutely entitled to their opinion. However if someone is going to make a definitive statement about astrology, especially if it is tied to a data set, they should understand what it is they are trying to argue.