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ATC or Grigri? Official MP survey
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Oct 21, 2016
Ever been dropped? Ever dropped someone? Collecting some data for a Mountain Project analysis to be featured on the blog in the next month or so. Goal: determining once or for all which is safer in the hands of an average user: an ATC or a grigri. Anonymous 60-second survey below:

docs.google.com/forms/d/e/1FAI...
Corey Buhay
Joined Aug 19, 2015
0 points
Oct 21, 2016
Rock Climbing Photo: Rock wars, Red River Gorge
You really think that a survey of people who self-select into taking your survey from a forum post has any validity whatsoever? This doesn't even pass the most generous sniff tests for survey validity, and serves only to mislead.

You want to answer this question for real? PM me, and we can talk. In the meantime, take the "official" down before you embarrass yourself.
shoo
Joined Aug 9, 2010
86 points
Oct 21, 2016
Rock Climbing Photo: Belaying 2nd (or was it 3rd? 4th?) on Turk's Head ...
There are mountains of scientifically collected data on this that are a much better basis for drawing a conclusion. I'll save you the Googling: Grigris are, by far, safer. Their accidents are just over reported because they're so surprising. Ted Pinson
From Chicago, IL
Joined Jul 11, 2014
178 points
Oct 21, 2016
Rock Climbing Photo: Epic belay shot
Needs a comparison for how often each style is used.

E.g. I only leave the ground if belayed with a grigri, cinch, or jul, so if a user like me were to log a report the data is skewed without your dataset having a variable that you can use to correct for which device I choose to use
Medic741
From Red Hook, New York
Joined Apr 1, 2012
288 points
Oct 21, 2016
Ted, that's what I'm trying to find out. If you have access to more scientifically collected data, please PM me; I'd love to see it! However, I've been unable to find any conclusive evidence for the safety of one device over the other (outside the gym) as of the posting of this survey.

Shoo, I agree that survey respondents will be self-selecting in that they're more likely to respond if they've been dropped, but I have no reason to believe Mountain Project users would be predisposed to use a Grigri over an ATC or vice versa. Therefore, a comparison of the two should still be valid if corrections for a small sample size are applied. And though any evidence will still anecdotal, some numbers would shed more light than current forum discussions do. This is also meant to be used in conjunction with other sources, not as standalone evidence. If you have any more concerns, please feel free to PM me; I appreciate your feedback.

Medic741 - That's an excellent point. Please mention that in the comment/clarification section of the survey, if you haven't already. I'll see if I can add another question.
Corey Buhay
Joined Aug 19, 2015
0 points
Oct 24, 2016
Rock Climbing Photo: Rock wars, Red River Gorge
CoreyLynn wrote:
Shoo, I agree that survey respondents will be self-selecting in that they're more likely to respond if they've been dropped, but I have no reason to believe Mountain Project users would be predisposed to use a Grigri over an ATC or vice versa. Therefore, a comparison of the two should still be valid if corrections for a small sample size are applied.


You are both wrong about your assumption that MP users (and moreso MP users reading a very specific sub-forum who bother to click your link) will not differentially respond based on own experience AND ALSO missing a hugely important second set of factors that are completely unaccounted for.

1) This is a charged issue, particularly for readers of this forum. People feel very strongly about "dangers" of the grigri. You are going to get a huge amount of people who are out to prove either that grigris are dangerous / totally safe based on their anecdotal experience. Your problem is that you have no way of knowing the relative strength of those biases. Some of those biases are in opposite directions.

You are making the mistake of believing that ambiguous net direction of bias strengthens conclusions, when the opposite is in fact true. If you know you are biased, but don't know what direction you are biased in, you cannot make any conclusions. If you know what net direction the bias is expected to be, you have a chance that the data will come out in such a way that some conclusions can still be made.

2) You are completely failing to understand the differences in how the two devices are used. The kinds of people and scenarios in which people use the two devices are totally different, and not in a way that is easily accountable (nor do you even attempt to do so with a BS measure of "years of climbing"). These are NOT fair comparisons. Again, you have an ambiguous direction of bias problem, complicated with the self-reporting biases outlined above, although in this case one general direction of bias is likely to be a bit stronger overall.

3) Forget about the "small sample correction" nonsense. That is not even close to your biggest problem here.

CoreyLynn wrote:
And though any evidence will still anecdotal, some numbers would shed more light than current forum discussions do


No. Bad data masquerading as good data serve no useful purpose in public discourse. Your results are meaningless, and are actively misleading except in the absurdly unlikely case where all of the numerous biases in your survey magically cancel each other out.

Again, there are good ways to do this and actually put some real numbers on this, but you are not doing any of them. You have good intent, but you are doing a bad thing. Please cancel this.
shoo
Joined Aug 9, 2010
86 points
Oct 24, 2016
Is this for a school project? Cory F
From Blacksburg, VA
Joined Jun 20, 2016
8 points
Oct 24, 2016
CoreyLynn - I think it absolutely fantastic that you are doing this survey.

It seems the trick is you need a common denominator for comparing the two devices-- and this denominator is really hard to get. Like number of drops per number of falls. Looks like you are going to do drops per years of climbing. But then there is the factor that people who are catching lots of falls (sportclimbers) tend to use a grigri. Maybe people could estimate the number of falls they catch per year.

Shoo - sooo, rather than just take aim at this survey, how would you set up a survey that, in your **opinion**, is not biased?
JohnnyG
Joined Nov 30, 2009
33 points
Oct 24, 2016
Don't listen to Shoo: his comments and opinions are as meaningless as your internet survey may ultimately be. It's a MP-forum discussion after all. Nonetheless it's interesting data, and I enjoy seeing what people are using. Ancent
From Reno, NV
Joined Apr 10, 2015
90 points
Administrator
Oct 24, 2016
Rock Climbing Photo: Enter the Colossus
Surprised that twice as many people have reported being dropped on ATC vs Gri Gri. Well I mean not really but I didnt think it would be that high.

When your life depends on it, GriGri
Morgan Patterson
Joined Oct 13, 2009
8,897 points
Oct 24, 2016
Rock Climbing Photo: Me trying to FA Solomon Grundy
Nothing to raise people's hackles like calling something official for no reason other than to sound important...

Also, where's the love for Smart/clickup/megajul style devices?

Wish there was a hear-say category...
EthanC
Joined Jun 17, 2013
287 points
Oct 24, 2016
Rock Climbing Photo: Top of Rainbow Buttress
To the 3 people who have claimed to been dropped 10 times by their belayer... what?! Andrew Yasso
From Las Vegas, NV
Joined Sep 9, 2012
233 points
Oct 24, 2016
Rock Climbing Photo: Out of the blue.  Photo by Mike W.
EthanC wrote:
Nothing to raise people's hackles like calling something official for no reason other than to sound important... Also, where's the love for Smart/clickup/megajul style devices? Wish there was a hear-say category...



It worked for the Federal Reserve and Federal Express, neither of which are federal.
Greg D
From Here
Joined Apr 5, 2006
999 points
Oct 24, 2016
Rock Climbing Photo: Rock wars, Red River Gorge
JohnnyG wrote:
Shoo - sooo, rather than just take aim at this survey, how would you set up a survey that, in your **opinion**, is not biased?


Basically any sampling strategy that relies heavily on self-selection into the sample is out, pretty much automatically.

Getting a real answer to this question would require some leg-work in the best case scenario, with reductions in bias depending strongly on just how much leg-work you're willing to do. An absolutely minimal amount of work would probably require cold call phone polling from a "climber" database (AMC, gym records, etc).

I am happy to do some pro bono work designing a study here, but my professional/research associations would prevent me from from doing much more than design and advising.

Ancent wrote:
Don't listen to Shoo: his comments and opinions are as meaningless as your internet survey may ultimately be.


My "meaningless opinions" have credentials to back them, and you're almost certain to get the same answer from anyone with a relevant/comparable background. Once again, PM me if you want more info.
shoo
Joined Aug 9, 2010
86 points
Oct 24, 2016
Shoo is right in terms of survey design. This is not a sample survey that can be generalized to any population. It is only a questionnaire of those who respond.

And yeah, those people with 10 drops need to find a different hobby.
Owen Witesman
From Springville, UT
Joined Feb 25, 2014
121 points
Administrator
Oct 24, 2016
Rock Climbing Photo: Enter the Colossus
shoo wrote:
my professional/research associations would prevent me from from doing much more than design and advising.


I wouldn't argue with this man about stats... sounds like you'll loose 100% of the time.
Morgan Patterson
Joined Oct 13, 2009
8,897 points
Oct 24, 2016
Owen Witesman wrote:
Shoo is right in terms of survey design.


Agreed. Is the survey for personal interests? Or part of something larger?
Cory F
From Blacksburg, VA
Joined Jun 20, 2016
8 points
Oct 24, 2016
Cory F wrote:
Agreed. Is the survey for personal interests? Or part of something larger?


You've asked twice now, but CoreyLynn says what the info is for in the originating post...
Brett Kitchen
Joined Apr 25, 2016
10 points
Oct 24, 2016
Rock Climbing Photo: Killis Howard?
No hip belay option?! Tim Lutz
Joined Aug 9, 2012
43 points
Oct 24, 2016
shoo wrote:
Basically any sampling strategy that relies heavily on self-selection into the sample is out, pretty much automatically. Getting a real answer to this question would require some leg-work in the best case scenario, with reductions in bias depending strongly on just how much leg-work you're willing to do. An absolutely minimal amount of work would probably require cold call phone polling from a "climber" database (AMC, gym records, etc). I am happy to do some pro bono work designing a study here, but my professional/research associations would prevent me from from doing much more than design and advising. My "meaningless opinions" have credentials to back them, and you're almost certain to get the same answer from anyone with a relevant/comparable background. Once again, PM me if you want more info.


I see your point, and I agree with you.

This gets to really basic questions about data and decision making. I don't think it's appropriate to completely disregard this study because of self selection, especially since the alternatives is a much more costly study.

I work with a lot of imperfect data as a geologist, and we make decisions on imperfect data in all fields. Basically, we have to make decisions whether there is perfect data or not. And I would argue that some data is better than no data.
JohnnyG
Joined Nov 30, 2009
33 points
Oct 24, 2016
Rock Climbing Photo: Rock wars, Red River Gorge
JohnnyG wrote:
And I would argue that some data is better than no data.


Some data is better than no data for those that have the education / training / experience / time / attention span to understand the limitations and biases of those data. Unfortunately, the typical MP user does not have those luxuries.

It is 2016. It is easier than ever to collect and spread information, good or bad. If it is more likely that the information that will be spread is misunderstood than understood by those who would be making decisions on that data, then no data is better than some data.

Knowing this, it is irresponsible, and possibly downright dangerous, to produce shitty stats and endorse them with an otherwise respectable brand, no matter how many disclaimers you use.
shoo
Joined Aug 9, 2010
86 points
Oct 24, 2016
Brett, I'm an idiot. I read the OP before coffee. embarrassing... Cory F
From Blacksburg, VA
Joined Jun 20, 2016
8 points
Oct 24, 2016
I am amazed that no one has thus far pointed out that this is a pointless survey incapable of illuminating anything because IT'S THE BELAYER, NOT THE DEVICE.

Full disclosure: I almost never sport climb; it is a sub-genre of climbing (not climbing) that I just don't find very interesting. Unlike some above, I DON'T want my belayer using a gri-gri for the things I do (ice, trad, alpine) because

1) a Gri-gri is heavier
2) a Gri-gri is more expensive
3) a Gri-gri is more complex
4) a Gri-gri doesn't do double ropes
5) a Gri-gri doesn't do icy ropes

Why does that matter? Because in my estimation if you actually bought the damn thing then you're a little dense and I don't want dense people belaying me. Dense people can figure out to screw up anything, there is no such thing as a fool proof device for that reason. If you can't figure out how to use a simple device like an ATC correctly, then I don't want you belaying me. In 30+ years I've never dropped nor been dropped.
Jim Corbett
Joined Sep 19, 2008
15 points
Oct 24, 2016
Rock Climbing Photo: Killis Howard?
Jim Corbett wrote:
IT'S THE BELAYER, NOT THE DEVICE.


exactly why I only use the hip belay. If the climber can't handle ass technologies from the 70s, well, screw them!

Jim Corbett wrote:
Full disclosure: I almost never sport climb; it is a sub-genre of climbing (not climbing) that I just don't find very interesting. .


or perhaps you just suck at being stronger than a teenage girl at the gym?
Tim Lutz
Joined Aug 9, 2012
43 points
General Admin
Oct 24, 2016
To help clarify, Corey is working on a story for our blog. We definitely welcome all input and advice (and encourage you to take the quick survey). It's common for a publication to poll its community, and that's what we're doing here, as a starting point to provide color and substance to the article. Shannon Davis
Joined Sep 15, 2015
96 points
Oct 24, 2016
Rock Climbing Photo: kramer
I belay with both, at the same time. Just like double bagging it, its safer that way. Hobo Greg
Joined Mar 30, 2016
64 points


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