Is anecdotal evidence dangerous?

[JeffG]

Is anecdotal evidence dangerous?

Only when it's wrong.

That's when you know you are having a bad day.

 

[drl]

Anecdotal evidence per se is not dangerous. Drawing inappropriate conclusions on the basis of anecdotal evidence is!

 

[Teamcasa]

Let's suppose a diver commutes in a car and gets sick at depth on a 100 ft Ice Dive.

Then the next month, it happens again to someone else who made a commute to a dive, in the same ratty car.

If you are resistant to anecdotal evidence, you will see them as two isolated random events.

Otherwise, you will be calling the guy to check his exhaust system, or looking for rusted out hole in the floor, etc.

I could argue that anecdotal evidence is very useful, and that we use it more often than we even realize.

Maybe.
Could they also have had their tanks filled at the same place?

 

[Cacia]

I use an anecdote to direct a relevant question, not give an answer.

Maybe.
Could they also have had their tanks filled at the same place?

Sure...but start upstream with common variables. The danger, IMV, is making assumptions or *proof* based on what should really just help frame the investigation or question...or hypothesis.

Both sets of evidence serve different, yet valuable, purposes. It should never be "either" "or".

 

[perdidochas]

I have read so many posts that use only anecdotal evidence to support a particular point of view. To me this is down right dangerous in some cases. When it comes to diving, I see this as very troubling. How many times have we all read “ I’ve been to 160’ fsw on air and did fine” or “I came up from 100’ and did not do a safety stop” or “I don’t get narcked at 120’ fsw”. This sends a message that if I did it, you should be fine so go ahead and try it! I am always dubious when the only evidence is anecdotal.

I believe in the premise that science trumps anecdotal evidence every time. This not to say some have in fact done some of these things but is it safe for anyone, no. So when someone presents a situation where the only evidence is anecdotal, do more research before trusting the information.


.

I think anecdotal evidence is ok, provided it is used by the person making the observation. For example, for me, in diving in 72 degree water, a 3mm wetsuit is sufficient. That's an ok usage of the anecdotal evidence. Will that work for the population as a whole? Probably not.

 

[Teamcasa]

I use an anecdote to direct a relevant question, not give an answer.

Maybe.
Could they also have had their tanks filled at the same place?

Sure...but start upstream with common variables.

But that’s not anecdotal evidence, they are real clues to a real problem. Anecdotal evidence is nothing more than a casual observation of a situation, not a real investigation. The hole in the floor or testing the gas at the compressor are factual, not anecdotal.

 

[Cacia]

For me, it (and every single thing in life) is about processing variables and giving them appropriate weight.

I am arguing that anecdotes provide powerful, valuable clues. I will only rarely say that women are better at this or that--but processing from more areas of the brain, and using subjective and objective information simultaneously, we are acutely superior, generally speaking. It is a primal blend of knowledge and instinct, probably based on survival. Men have lost it in the quest to be superior linear thinkers. They generally don't value it either. It keeps me alive.

 

[Thalassamania]

Maybe, but your ability to process spacial relationships is right up there with our asking directions.

 

[Cacia]

..that is true

but hey...failing to ask for directions is closely related to dismissing anecdotal clues!

Thank God for Garmin Nuvi's, that is all I can say. Men accept it so much better from the man speaking with a British accent than from me.

 

[everlasting]

This was mentioned a little bit early on the in the thread, but I wanted to go back to it.

Even when examining scientific studies, we have to remain vigilant in our interpretations of data and the applicability of it to the wider community. And, perhaps more importantly, we also have to remember that scientists are human too, with as many inherent biases in their work as anyone else. Science is a career, albeit one that stresses logic and a desire for truth, but a career nonetheless. Scientists will fudge their own data (there have been many instances of photoshoped data, even). Scientists will try to salvage a failed project by twisting the data as much as possible and finding correlations just to publish SOMETHING, because their careers depend on it. Science aims to be logical, but still encounters the same human pitfalls.

I'm not saying that there are no merits to science or that all scientists are simply trying to further their careers (I don't believe either of those things!), but I do believe that we have to examine science much more stringently than we do anecdotal evidence. We can judge the merits of anecdotal evidence through our own knowledge (some that was acquired though experience, some anecdotal, some from scientific research). But judging the merits of a scientific study when you're not familiar with the techniques used, standards of the field, etc? A lot more of a challenge, in my opinion. In the end, scientific evidence is still taken on faith. And while blind belief in anecdotal evidence is dangerous, so is not recognizing the foundation of faith that underlies belief in science, as well as the limitations of scientific study.