I need a well known, easily understood example of bad science (i.e. bunk) for a persuasive argument I’m going to make.
It should be a case of the researcher wanting to get to a certain conclusion, collecting faulty data, and then on top of that drawing illogical conclusions from the data, i.e. he doing anything and everything possible to support the desired conclusion and calling his path to get there “science”. (It wouldn’t hurt if he was then discredited and hounded out of his profession.)
The example should be both an egregious misuse of the scientific method (like the Regnerus Affair) and guaranteed to be well known to the layman. As soon as I mention the example, the average reasonably well read listener should immediately know what I’m talking about.
Edit: it should be known in popular culture (in the U.S. at least) as a scientific scandal.