Anecdotal as in subjective and non-representative in regard to a purportedly objective assertion has nothing to do with the laws of evidence and hearsay. The laws of evidence are to limit the jury’s exposure to prejudicial evidence that has little probative value. Anecdotal evidence as I meant it and understood it, and how I think most people would, is in regard to a scientific study, where anecdotal evidence doesn’t say much, if anything. An example of this would be: my great grandfather smoked and lived until 110 when he died from being hit by a drunk driver. This is evidence that smoking is less likely to kill you than a drunk driver. Obviously, one person’s experience a rule makes not. This is anecdotal evidence.
Wikipedia, while useful, is not a particularly credible or persuasive source. It reminds me (l’havdil) of R’ Ribiat’s 4 volume hilchos shabbos set. Comprehensive, somewhat organized, innaccurate as to the bottom line, and a goldmine of additional sources.