Now, while both of the above statements are true - anecdotal reports are not strong of evidence and just because one event follows another doesn't mean that they are related - the ND movement likes to beat people over the head with these lines to the point of absurdity. In my experience, they will disbelieve every anecdotal report and will simply refuse to consider that a temporal relation can have any sort of significance whatsoever.
You think that your child regressed into autism immediately after getting a shot, you just missed the earlier signs.
You think that a diet helped your child, you are imagining things.
You think that a specific intervention really helped - you don't know what they would have done without the intervention, maybe they would have progressed naturally.
You really can't read anything that the movement writes for any length of time without running head first into some form of these statements. I think these are almost slogans for the movement, right after their autism isn't a disorder and acceptance rhetoric.
So, imagine my surprise when over at the neurodiversity blog, we have statements by Kathleen Seidel using anecdotal parent reports from message boards as some sort of "proof" that OSR #1 has side effects -
Contrary to Prof. Haley’s suggestion that there have been no “severe” side effects associated with OSR, and contrary to Dr. Kartzinel’s assertion that adverse events have been “rare,” as soon as OSR went on the market, numerous anecdotal reports of side effects began to appear on online discussion groups frequented by parents of autistic children — most notably the 6,465-member ChelatingKids2 Yahoo! group. The volume of these reports slowed after the establishment of several new restricted-membership groups for discussion of OSR were established in the Spring of 2009, and since ChelatingKids2 was suspended the following August. Notwithstanding the slowing of open public discussion about OSR by its purchasers, the informal reports that have accumulated since its introduction into commerce provide compelling indications of OSR’s potential to significantly, unpredictably alter human fluid balance, disrupt mineral metabolism, and negatively affect gastrointestinal, respiratory and immune function, and should give pause to anyone tempted to trust the safety assurances of those who stand to profit from its continued sale.You have got to be kidding me, parental reports are now a compelling indication? What the hell, have these people never heard of intellectual honesty? If you are going to take an approach, then at have the integrity to stick to your beliefs and not flip flop at a moments notice. Parental reports can't be a valid source of information on one hand and completely disregarded on the other.