- Messages
- 22,171
- Reaction score
- 2,791
- # of dives
- 5000 - ∞
Anecdotes lead to hypotheses, hypotheses lead to experiments, experiments lead to knowledge. Thats the system.I will agree with you: they are not in fact "anecdotes". They are comparing apples to oranges, or goats to humans as it were.
One of the first evidences of "bubbles" as being a part of DCS was a researcher (Haldane, I believe) seeing a bubble in a serpents eye that he had just decompressed. Is this an anecdote, a data point or both? As was pointed out, any dive whether it resulted in an incidence of DCS or not, is merely an anecdote. Combine a number of these together and we have a "study". .
The final product was not based on goat testing, goats were used in initial experimentation for a very specific reason. Do you know why goats were used in the early experiments?
Actually the real problem is a public is woefully unconversant with scientific method and terminology.The real problem is the extrapolation of these data points.
For example:
Actually I not only make that statement (160 for 5 I think was the schedule) but will expand on it to say that Ive done it more than once and I suspect it has been done quite literally thousands of times, by many different people since the U.S. Navy Tables came out. The 160 for 5 schedule was never one that was felt to be suspect.One person has claimed that they bounced to 165 fsw and had no effects. Can we extrapolate that data to everyone?
Now lets deal with the next piece of misinformation that your spreading:
Contrary to the urban myth that the U.S. Navy tables were developed for, and exclusively tested on, young peak-fitness seamen, I have it from Bob Workman himself that at least one of the test groups was composed almost entirely of middle-aged, overweight, hard drinking, cigar-chomping, U.S. Navy Chiefs.What if we had a thousand young and fit divers bounce to 165 fsw? Would no DCS provide us incontrovertible proof that a dumpy 45 YO would have no problem bouncing to 45? No, now it becomes a SWAG.
Once the tables are developed from a hypothesis, tested experimentally with animals and tweaked, test experimentally with humans and tweaked and then tweaked on a regular basis as a result of operational experience, theyre not anecdotal. What then is anecdotal are reports of people who got bent diving inside of the tables. As has been observed before, many anecdotal cases of undeserved bends likely result from bad ascent procedures.How about if the water is 20 degrees colder than the sample? What if... (put your own variable here)???
The real problem is not the anecdote, but the fallacious conclusion drawn from the data at hand. If I said I did a half hour dive to 60 foot and did not suffer any symptoms of DCS, this would not only fall within the traditional data (as defined by the tables) but it would also be an anecdote for me to go on. It's the anecdotes that seem to DEFY our understanding of decompression physiology that disturb us the most.