"Pseudoscientists – those pretending to do science (maybe even sincerely believing they are doing science) but who get the process profoundly wrong, use anomalies in a different way. They often engage it what we call anomaly hunting – looking for apparent anomalies. They are not, however, looking for clues to a deeper understanding of reality. They are often hunting for anomalies in service to the overarching pseudoscientific process of reverse engineering scientific conclusions."
"What this means is that pseudoscience almost always works backwards – that is its primary malfunction, starting with a desired conclusion and then looking for evidence and twisting logic to support that conclusion."
"With regard to anomalies the logic often works like this: “If my pet theory is true then when I look at the data I will find anomalies.” The unstated major premise of this logic is that if their pet theory were not true then they would not find anomalies. This is naive, however. Another component of this line of argument is the broad definition of anomaly."
"In real science an anomaly is only declared so after exhaustive efforts to explain it within existing theories fail. Astronomers checked and quadruple checked their calculations of Mercury’s orbit. They hypothesized that there were other bodies in the solar system exerting gravitational effects on Mercury. They did everything they could to explain Mercury’s orbit within Newtonian physics. This process didn't really end until Einstein explained the orbit of Mercury."
"What pseudoscientists often fail to recognize is that if you take any complex natural phenomenon, historical event, object or process and you look for apparent anomalies (broadly defined), you will find them. Humans are great at pattern recognition, and so if you look for coincidence in the data you will detect them. You will also find features that resulted from a complex interplay if unique events and therefore will be impossible to prove a specific explanation."
http://theness.com/neurologicablog/index.php/anomaly-hunting/