|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
On Mon, 20 Mar 2017 13:54:00 -0400, Frank Krygowski
wrote: On 3/19/2017 9:08 PM, Jeff Liebermann wrote: On Sun, 19 Mar 2017 15:24:31 -0700, sms wrote: On 3/19/2017 2:02 PM, Jeff Liebermann wrote: Now I have to go cash my check from Reelight. Such things are usually done by "loaning" you test samples of the products, and then "forgetting" to recover them. In theory, you're expected to declare the value of such samples as income for tax purposes. Payments of cash or checks are rare unless you are hired as a consultant. Yes, but a couple of people in this group insist that the only reason I favor good lights is because I am getting paid by light companies. The fact that it isn't true doesn't matter to them. They will come up with any excuse they can think of to try to ignore the data. If you arrange with Reelight to send your persecutors some free sample lights, they might be inclined to reconsider their position. The problem here is that if you are repeatedly accused of some dastardly crime against the cycling multitudes, such as accepting payola from a vendor, the mere repetition of the accusation will eventually cause it to become a truism. Anyone who searches the web for bicycle lighting recommendations will eventually blunder across those accusations. The casual reader is more likely to accept the accusations at face value than to continue reading the subsequent discussion material. You might consider writing a explanation, FAQ, or manifesto on the topic, which you can reference in future discussions on the topic. If Mr. Scharf were to do that, honesty would require including quotes of his original statements saying something like "please start your purchases from my website" and bragging about his "guerilla marketing to all aspects of the bicycling community" - or whatever the precise wording was. (I wish now I'd saved a copy.) guerilla ~ a member of an irregular armed force that fights by sabotage and harassment. -- Cheers, John B. |
Ads |
#33
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
On Mon, 20 Mar 2017 14:26:35 -0700, sms
wrote: Anytime someone doesn't like the results of a study they try to pick it apart. Actually, common practice is to first blame someone and then pick apart the argument. However, I prefer to undermine the study and let it collapse under its own weight. If "pick it apart" is an unacceptable method of debating the merits of a study, what would you consider to be an acceptable method for this newsgroup? I could use propaganda, various logical fallacies, anecdotal evidence, my personal feelings, or perhaps fabricate a contradictory study. Methinks that "pick it apart" is the same as breaking down the study into individual claims and seeing how each one holds together under stress. Perhaps it would be helpful if I explained how I analyze such studies. I've done it in this newsgroup at least a dozen times, but have never really explained how it's done. First, I find the original study. This is the most difficult part because studies are now hidden behind pay walls, revised continuously, and "edited for publication" in different lengths and forms. Once I have the original study, I try to determine who paid for it. That's because the conclusions and summary of the study are owned by whomever paid for the study, while the actual data and calculations are owned by the academics, scientists, students, and statisticians that ran the study. Often these are different or even in opposition. I then read the study in as much detail as I have time available. That's when the differences between the study and the web page announcing the study become apparent. In medical studies and surveys, I've seen claims that are quite the opposite of what the research shows, usually because the claims support a product or remedy. From this point, my approach varies depending on what I'm trying to demonstrate, prove, denounce, or evaluate. Usually, pointing out inconsistencies, gross omissions, and occasionally math errors is sufficient. In this case, I have been unable to find the study in either the original Danish or an English translation. Therefore, I have not read the original and have had to work with a brief summary from some unknown report or survey that apparently has been quoted and recycled extensively. The best I could do is point out that the percentage cited was meaningless without also disclosing the statistical population (number of participants in the test). This is hardly "pick it apart". So, I'll pick at it some more. One problem with claiming that flashing tail lights reduce accidents is that there just might not be any correlation between tail lights and accidents at all. Just because two things correlate (follow the same trends) does not mean that one causes the other. Some ludicrous examples: http://www.tylervigen.com/spurious-correlations So, how does one prove that flashing tail lights actually cause a reduction in accidents and that the 30% drop was not a coincidence? Well, one way is play the record backwards. Instead of giving out tail lights, find a group that has been using flashing tail lights for some time and take away their tail lights. If accidents increase, then there just might be a connection. Perhaps programming the tail lights so that they flash at different rates under the assumption that a faster flashing rate is more visible and therefore safer. I could dream up a few more tests, but basically the idea is to do things that test for a connection between flashing tail lights and accidents. The other part of the problem is that it's very easy to demonstrate that something is unsafe. All that's needed is one accident. However, it's impossible prove that anything is safe because there will always be accidents caused by coincidence or disconnected correlations. Have I "picked apart" your one liner sufficiently? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#34
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
On Mon, 20 Mar 2017 16:13:39 -0400, Frank Krygowski
wrote: On 3/20/2017 9:59 AM, jbeattie wrote: Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle Don't ride in Auckland, even with a blinky. Interesting study, with weird results. Seemed the group that was just "occasionally conspicuous" had the lowest crash rate. (...) I see one problem with the study. There's little correlation between accident crash rate and being conspicuous. The problem that drives of vehicles that hit bicyclists almost always proclaim that they didn't see the bicyclist. That might be because the bicyclist was not easily visible, but could also be because the driver wasn't paying attention, was distracted, in desperate need of corrective vision, or was under the influence of booze, drugs, or passengers. For these drivers no amount of conspicuous clothing or flashing lights will improve their driving. That begs the question of what is the ratio of attentive drivers to impaired losers? I don't know. If I arbitrarily assign a 50/50 distribution, then I'll probably find that the overwhelming majority of bicycle crashes are caused by the impaired losers. That means that visibility has little effect on the conscientious drivers, who will probably be paying attention to their driving, and little effect on the impaired losers, who will probably be immune to any improvements in visibility. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#35
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights forBicycles.
On 20/03/17 16:54, Jeff Liebermann wrote:
On Mon, 20 Mar 2017 06:59:40 -0700 (PDT), jbeattie wrote: Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle Don't ride in Auckland, even with a blinky. -- Jay Beattie. 187 accidents among 162 participants in 6.4 years? The carnage in the streets must be awful. I would expect all cyclists to be exterminated within their expected lifetimes. If I ride for 64 years of my life, I would expect to get hit about 10 times. Maybe bicycle fashion is the problem? https://www.google.com/search?q=dazzle+camouflage+bicycle+jacket&tbm=isch They won't hold off a New York SUV, but they may stop you getting torpedoed by a German submarine :-) https://en.wikipedia.org/wiki/Dazzle...1)_cropped.jpg |
#36
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights forBicycles.
On 3/20/2017 11:06 PM, Jeff Liebermann wrote:
On Mon, 20 Mar 2017 14:26:35 -0700, sms wrote: Anytime someone doesn't like the results of a study they try to pick it apart. Actually, common practice is to first blame someone and then pick apart the argument. However, I prefer to undermine the study and let it collapse under its own weight. If "pick it apart" is an unacceptable method of debating the merits of a study, what would you consider to be an acceptable method for this newsgroup? I could use propaganda, various logical fallacies, anecdotal evidence, my personal feelings, or perhaps fabricate a contradictory study. Methinks that "pick it apart" is the same as breaking down the study into individual claims and seeing how each one holds together under stress. There is a tendency to nitpick little things and then to declare the entire study as worthless, when in fact, other than perhaps in drug trials, there is just not going to be a "perfect study." Yet the goal of the study was to determine if flashing lights were effective, and if so, use the data to remove a ban on flashing lights. The company that was involved in the study certainly had a vested interest in the outcome, but they are only one of a multitude of companies that are benefiting from the outcome. Yet we used to often see studies that were almost completely bogus, touted as proving something. I recall one study on cycling rates following the imposition of an MHL where those doing the study decided that they would simply not count a large group of cyclists that passed by the counting location because they didn't think that they were normal cycling traffic. That was a study to "prove" that MHLs caused a decrease in cycling rates. Yet the Odense study was actually pretty good as far as these things go, with two control groups so factors other than the presence or absence of lights cancelled out. And while it was only a 32% reduction in accident rates, the fact that 85% cyclists "felt safer" is also a positive outcome if it leads to higher cycling rates. Part of the reason that cycling rates trend up following the passing of an MHL is probably the same reason--"oh, if I wear a helmet then I'll be safe." |
#37
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
On Monday, March 20, 2017 at 2:29:18 PM UTC-7, sms wrote:
On 3/20/2017 1:40 PM, wrote: No worries, I do not think you are a paid shill - just deluded............... Gee, thanks. Jeff showed himself to be extremely knowledgeable of statistics and noted the chief problem with the study. They did NOT show actual numbers because Reelights could not afford to shell out hundreds of thousands of free lights. So this study was probably confined to perhaps a thousand and the change in accidents was in fact statistically irrelevant. So taken in pure percentages and presented as if it had meaning it makes for a good sales pitch and gives some undergraduate a paper to write. Anytime someone doesn't like the results of a study they try to pick it apart. If they did not want it picked apart they only had to provide the actual numbers. And they didn't. Why do you suppose that was? |
#38
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights forBicycles.
On 3/21/2017 1:06 AM, Jeff Liebermann wrote:
On Mon, 20 Mar 2017 14:26:35 -0700, sms wrote: Anytime someone doesn't like the results of a study they try to pick it apart. Actually, common practice is to first blame someone and then pick apart the argument. However, I prefer to undermine the study and let it collapse under its own weight. If "pick it apart" is an unacceptable method of debating the merits of a study, what would you consider to be an acceptable method for this newsgroup? I could use propaganda, various logical fallacies, anecdotal evidence, my personal feelings, or perhaps fabricate a contradictory study. Methinks that "pick it apart" is the same as breaking down the study into individual claims and seeing how each one holds together under stress. Perhaps it would be helpful if I explained how I analyze such studies. I've done it in this newsgroup at least a dozen times, but have never really explained how it's done. First, I find the original study. This is the most difficult part because studies are now hidden behind pay walls, revised continuously, and "edited for publication" in different lengths and forms. Once I have the original study, I try to determine who paid for it. That's because the conclusions and summary of the study are owned by whomever paid for the study, while the actual data and calculations are owned by the academics, scientists, students, and statisticians that ran the study. Often these are different or even in opposition. I then read the study in as much detail as I have time available. That's when the differences between the study and the web page announcing the study become apparent. In medical studies and surveys, I've seen claims that are quite the opposite of what the research shows, usually because the claims support a product or remedy. From this point, my approach varies depending on what I'm trying to demonstrate, prove, denounce, or evaluate. Usually, pointing out inconsistencies, gross omissions, and occasionally math errors is sufficient. In this case, I have been unable to find the study in either the original Danish or an English translation. Therefore, I have not read the original and have had to work with a brief summary from some unknown report or survey that apparently has been quoted and recycled extensively. The best I could do is point out that the percentage cited was meaningless without also disclosing the statistical population (number of participants in the test). This is hardly "pick it apart". So, I'll pick at it some more. One problem with claiming that flashing tail lights reduce accidents is that there just might not be any correlation between tail lights and accidents at all. Just because two things correlate (follow the same trends) does not mean that one causes the other. Some ludicrous examples: http://www.tylervigen.com/spurious-correlations So, how does one prove that flashing tail lights actually cause a reduction in accidents and that the 30% drop was not a coincidence? Well, one way is play the record backwards. Instead of giving out tail lights, find a group that has been using flashing tail lights for some time and take away their tail lights. If accidents increase, then there just might be a connection. Perhaps programming the tail lights so that they flash at different rates under the assumption that a faster flashing rate is more visible and therefore safer. I could dream up a few more tests, but basically the idea is to do things that test for a connection between flashing tail lights and accidents. The other part of the problem is that it's very easy to demonstrate that something is unsafe. All that's needed is one accident. However, it's impossible prove that anything is safe because there will always be accidents caused by coincidence or disconnected correlations. Have I "picked apart" your one liner sufficiently? I don't know but significance and meaning may vary. Just read a newspaper headline about a "new drug found 70% better than aspirin". Of 3600 people over 5 years there were 2.3% heart attacks in the daily aspirin group and 1.6% heart attacks in the new new group. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#39
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
On Monday, March 20, 2017 at 7:42:32 PM UTC-7, John B. wrote:
Unfortunately it does not conceal the fact that what you stated, "a comparison of bike lights versus no bike lights", was not what the Odense study tested, nor was it the results of the study. But John, the whole point is that you have NO IDEA what they accomplished with a study that so obviously had such a small study group that they wouldn't even publish the size of it. You know that in statistical analysis concerning small percentages of injuries and fatalities as bicycle accidents that the study size has to be gigantic to reveal any pertinent information. So why would you pretend differently? |
#40
|
|||
|
|||
The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
On Monday, March 20, 2017 at 8:05:55 PM UTC-7, John B. wrote:
On Mon, 20 Mar 2017 14:01:55 -0400, Frank Krygowski wrote: On 3/20/2017 1:08 PM, sms wrote: On 3/19/2017 11:08 PM, John B. wrote: snip We need a double-blind study of accident rates where they use 65,536 different combinations of front and rear lumens, flashing and steady, battery and dynamo powered, performed in 128 different countries, over ten years, in a variety of lighting conditions. Until that study has been completed we can't be absolutely certain whether or not an increase in conspicuity is beneficial to cyclists, so it makes no sense for cyclists to make themselves more visible. Let's get the UN to commission this study. I'd have thought you'd take on the project as a volunteer. But you really should include those six foot (two meter) bicycle flags on vertical poles as part of the study. I still don't understand why the champion of "If it may possibly help" visibility doesn't use them. Or even better, sell them via his websites. Your competition is killing you! http://www.swagbrokers.com/Fiberglas...Pole-181810804 The various countries I have visited all seem to have rules and regulations that argue that a orange and white "checkerboard" flag flown from vehicles operating on airfields is a good thing. I well remember that when, as a young Airman stationed in Japan, one could even ride one's personal motorbike on the airfield if flying such a flag. If a checkered flag will "fend off" a big Boeing bomber it should prove equally effective in deterring a California SUV. I believe that if the State of California should mandate that every bicycle operated on the highways of the state must be equipped, and display, a (lets be reasonable here) a 2 foot square (i.e. 4 square feet) checkered flag it would immediately result in a substantial decrease in annual bicycle "accidents" and fatalities. If ridden at night the flag would obviously have to be illuminated in some manner but that is just details. John, how old are you? I spent four years in the Air Force in five different states and three different countries and never heard of such a requirement. I then spent three years in commercial aviation and never heard of such a thing either. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
New B&M Lights with Wide Beam and Daytime Mode Available | sms | Techniques | 74 | November 23rd 13 06:46 PM |
Flashing front light in daytime. | Nick[_4_] | UK | 22 | June 18th 08 12:28 PM |
Car daytime running lights | David Hansen | UK | 15 | March 25th 08 11:55 AM |
Daytime running lights | Martin Dann[_2_] | UK | 7 | February 12th 08 11:15 PM |
New University of Illinois Helmet Study ... | Edward Dolan | Recumbent Biking | 1 | May 8th 06 02:04 AM |