That evidence may be anecdotal is not a case for dismissing the evidence. Often people will say that an illustration is anecdotal meaning that the example shown does not in itself constitute definitive evidence of the apparent result. Let's say that an olympic ice skater has an awkward fall in a competition. That single case neither proves that he is a bad skater nor that he is a good skater who tends to perform poorly in certain cases. Multiple falls on multiple occasions are a clearer indicator. A friend today criticized what he called "anecdotal" cherry picking among the media following POTUS through Europe. But there is another view, the accumulation of gaffes can be taken for perhaps a significant attribute of POTUS. Anecdotal evidence is valuable in several ways; it gives a qualitative dimension to data, it can accumulate into statistical evidence, and it can give a nod to possible, maybe probable, trends. After a bit of recurrence, however, dismissing evidence because it is anecdotal is like dismissing an avalanche because it is snow.
-- Kilgore Forelle