Cherry picking

"Cherry picking" is the practice of collecting data which supports your point while systematically ignoring all contradictory data. This is a blatant violation of the scientific method and among scientists is generally considered to be unethical (see scientific misconduct and advocacy science).

A political example occurred in the 1990s, when the "black church burning epidemic" captured headlines:

• The CDR had systematically ignored fires set by blacks and those that occurred in the early part of the decade; it had also labeled some fires as arson that clearly were not — all in an apparent effort to make black church torchings appear to be an escalating phenomenon.

Even science journals have been fooled:

• Consider a report by three environmentalist authors back in 1998 in Journal of the American Medical Association (JAMA), analyzing male-female birth ratios between 1970 and 1990. The authors found male births declining, and predictably blamed man-made chemicals. Yet public data going back to 1940 showed gender ratios are always changing, for no obvious reason. Years that disproved their thesis were simply sliced out.

Here is statement widely used to promote the idea that global warming makes strong hurricanes more frequent:

• "... over the past 35 years ... A large increase was seen in the number and proportion of hurricanes reaching categories 4 and 5." [1]

Here is the rebuttal:

• "... not a trend. Rather, it is likely a part of the large interdecadal variations in the number of intense typhoons related to similar temporal fluctuations in the atmospheric environment." [2]