«Popper has this picture of the scientific attitude that involves taking risks: making bold claims, then gathering all the evidence you can think of that might knock them down. If they stand up to your attempts to falsify them, the claims are still in play. But, you keep that hard-headed attitude and keep you eyes open for further evidence that could falsify the claims. If you decide not to watch for such evidence — deciding, in effect, that because the claim hasn’t been falsified in however many attempts you’ve made to falsify it, it must be true — you’ve crossed the line to pseudo-science».

http://blogs.scientificamerican.com/doing-good-science/2011/10/04/drawing-the-line-between-science-and-pseudo-science/