Note that the amusingly high failure rate in that paper is in the condition where people were not looking at bicycles with their own eyes, and when they were, the vast majority of respondents did fine at the task.
Yes, when people were looking at a bicycle, they were able to draw a bicycle, which they were looking at.
The point is: if people understood how their bicycle worked, they’d be able to draw one even without having to literally have one in front of them as they drew it! Whereas their actual attempts to draw a bicycle (without having one to look at) showed that they really had no concept of how one worked—and this even for people who rode a bike daily.
Again: being able to draw a bicycle when you are, at that very time, looking at an actual bicycle, does not at all demonstrate understanding of the bike’s operation.
I agree that many people do not understand how bicycles work, if that was your point. My claim was that it is possible to look at a bicycle and understand how it works, not that it was inevitable for everybody who interacts with a bicycle to do so. I think the prevalence of misunderstanding of bicycles is not strong evidence against my claim, since my guess is that most people who interact with bicycles don’t spend time looking at them and trying to figure out how they work. If people looking at bicycles still couldn’t reproduce them, that would be strong evidence against my claim, but that was relatively uncommon.
[ETA: although I see how this undermines the idea that it only requires ‘a little’ thought, since that brings to mind thought that only takes a few seconds.]
Even having looked at a bike, there are details I don’t understand, but I think not enough that I’d dispute your claim.
Derailleurs, and the transmission from the break levers to the break pads, seem kind of magical to me. I’m not sure if there’s a detail I’m missing, or if they just work far better than I would have expected. Especially derailleurs—pulling laterally on the chain, a tiny amount, makes it move from one gear to another, even if the gears are very different sizes? (I suddenly wonder if the slow mo guys have done an episode on derailleurs.)
I wouldn’t be able to tell you how stability works, either.
I reckon I understand a fixie with stabiliser wheels well enough, though.
Understanding how it works and remembering details when asked out of context may be very different things. I wish the participants had been given follow-up questions about how it works, and then the exercises repeated when a bicycle was present.
The point is: if people understood how their bicycle worked, they’d be able to draw one even without having to literally have one in front of them as they drew it!
I don’t think this is actually true. Turning a conceptual understanding into an accurate drawing is a nontrivial skill. It requires substantial spatial visualization ability, as well as quite a bit of drawing skill—one who is not very skilled in drawing, like myself, might poorly draw one part of a bike, want to add two components to it, and then realize that there is no way to add a third component to the poor drawing without turning it into an illegible mess of ink. There is a reason technical drawing is an explicit course in engineering education.
I built a nontrivial construction yesterday, that I understand in great detail and personally designed in OpenSCAD beforehand, that I could not put on paper by hand in a way that is vaguely mechanically accurate, without a visual reference (be it the actual construction or the CAD model). At least, not in one try—I might manage if it I threw away the first three sketches.
Note that the amusingly high failure rate in that paper is in the condition where people were not looking at bicycles with their own eyes, and when they were, the vast majority of respondents did fine at the task.
Yes, when people were looking at a bicycle, they were able to draw a bicycle, which they were looking at.
The point is: if people understood how their bicycle worked, they’d be able to draw one even without having to literally have one in front of them as they drew it! Whereas their actual attempts to draw a bicycle (without having one to look at) showed that they really had no concept of how one worked—and this even for people who rode a bike daily.
Again: being able to draw a bicycle when you are, at that very time, looking at an actual bicycle, does not at all demonstrate understanding of the bike’s operation.
I agree that many people do not understand how bicycles work, if that was your point. My claim was that it is possible to look at a bicycle and understand how it works, not that it was inevitable for everybody who interacts with a bicycle to do so. I think the prevalence of misunderstanding of bicycles is not strong evidence against my claim, since my guess is that most people who interact with bicycles don’t spend time looking at them and trying to figure out how they work. If people looking at bicycles still couldn’t reproduce them, that would be strong evidence against my claim, but that was relatively uncommon.
[ETA: although I see how this undermines the idea that it only requires ‘a little’ thought, since that brings to mind thought that only takes a few seconds.]
Even having looked at a bike, there are details I don’t understand, but I think not enough that I’d dispute your claim.
Derailleurs, and the transmission from the break levers to the break pads, seem kind of magical to me. I’m not sure if there’s a detail I’m missing, or if they just work far better than I would have expected. Especially derailleurs—pulling laterally on the chain, a tiny amount, makes it move from one gear to another, even if the gears are very different sizes? (I suddenly wonder if the slow mo guys have done an episode on derailleurs.)
I wouldn’t be able to tell you how stability works, either.
I reckon I understand a fixie with stabiliser wheels well enough, though.
There are small grooves or bumps (depending on the design) on the sides of the gears that help lift the chain onto the next gear.
Understanding how it works and remembering details when asked out of context may be very different things. I wish the participants had been given follow-up questions about how it works, and then the exercises repeated when a bicycle was present.
An understanding that evaporates on questioning is no understanding at all.
I don’t think this is actually true. Turning a conceptual understanding into an accurate drawing is a nontrivial skill. It requires substantial spatial visualization ability, as well as quite a bit of drawing skill—one who is not very skilled in drawing, like myself, might poorly draw one part of a bike, want to add two components to it, and then realize that there is no way to add a third component to the poor drawing without turning it into an illegible mess of ink. There is a reason technical drawing is an explicit course in engineering education.
I built a nontrivial construction yesterday, that I understand in great detail and personally designed in OpenSCAD beforehand, that I could not put on paper by hand in a way that is vaguely mechanically accurate, without a visual reference (be it the actual construction or the CAD model). At least, not in one try—I might manage if it I threw away the first three sketches.