Slashdot Mirror
Toilet Paper Algorithms
ziani writes "Computer science professor and ex-Apple technologist Don Norman posits a new "forcing function" in toilet paper use algorithms." Browsing through his website is a good way to kill a couple of hours.
← Back to Stories (view on slashdot.org)
These days, I can just use a couple of VA Software stock certificates and get the same effect. Plus, it is cheaper than toilet paper!
Friends don't let friends use multiple inheritance.
I wonder if he was inspired by Snowcrash, and the long discussion of the issues related to toliet paper in the Fed Building in which yt's mom works? Sounds pretty similar, but less funny.
Academics, especially professors, spend a good deal of their time brown-nosing and kissing other people's asses in the hopes of securing yet another research grant. Hence, the seemingly odd fascination for toilet paper, the uses of.
"I have opinions of my own, strong opinions, but I don't always agree with them." -- George H. W. Bush
This topic is full of shit!
Table-ized A.I.
...I knew that degree in CS would come in handy some day.
"player 4 hit player 1 with 0 stroms"
Has anyone researched yet when a common-sense idea beomes an algorithm that computer scientist discuss?
I mean, ok, nice idea, but do we really need computer scientist for this (except for using buzzwords)?
Disclaimer: This post was written deliberately in the long-practiced computer science tradition of over-analyzing simple problems.
___
Cogito cogito, ergo cogito sum.
I think Emacs has a minor mode to enforce correct toilet paper selection.
t
The Japaneze have built several toilets which, when you're done answering nature's call, you reach on one side of the bowl where controls are. There you can clean your butt by having warm watter sprayed around the exit area, maybe some soap, rinse, and then blow dry.
:D
Don't forget to flush!
--
# Canmephians for a better Linux Kernel
$Stalag99{"URL"}="http://stalag99.net";
Decided to take a look, see what kind of dual-roll dispensers are available, and voila... a sale!
Don't know if it was deliberate or not, but what a great way to utilitze the Slashdot Effect...
"Sometimes a woman is a kind of religion, she can save your soul & set you free from all your sins" - Bad Examples
Me? Nah...
It's not *my* ass that I want every Microsoft EULA shoved up...
Xentax
You shouldn't verb words.
What kind of anal [retentive] person wastes time on scheduling/queuing algorithms for TP?!?!
I think this is a self-answering question if you think about it.
Table-ized A.I.
The article does a good job of analyzing which roll to choose, but neglects the most important question of installing toilet paper rolls.
Should the paper come over the top of the roll, or out from under the bottom?
Clearly, over the top is better, because no matter how long or short the loose end is, it is always on the front so you can find it. With the under the bottom system, the loose end can be hanging behind the roll and you have to roll it until you can grab it.
I would like to see one where you push a button to get the number of sheets. For example, there might be a 1, 2, and 3 button. Pushing a given button twice means that you get double that number. So, if you want 4 sheets, you push 2 twice.
Then again, I don't know what the prior person left on the button. Thus, maybe a foot peddle press for each sheet.
Also, why are the flush mechanisms so fragile? It seems every house and appartment I have ever lived in had problems with the flushing and fill mechanisms. They always leak, or get tangled up in odd ways, or settings drift over time, etc. Is QA bad? Or is it just a hard engineering problem to solve? Any craptologists out there?
Perhaps it is time for Digital Toilets. But, I don't want to know what happens during extended blackouts (which I have been in) or dead batteries.
I guess we are just stuck with crappy crappers.
Table-ized A.I.
Perhaps it is time for Digital Toilets
I already put my "Intel Inside" sticker on the bowl.
Table-ized A.I.
"Get your hands out of that cereal box! How many times have I told you never to open a new box until you've finished the last box?"
N4st0r, trixx0r h0bb1tz0rz! Th3y st0l3 0ur pr3c10uzz!
Members of the world. Fear no longer. The toilet paper issue is solved, once and for all. No nitwick professor can now waste you're hard earned tax money on this essentially small problem. I am glad it was solved by man-in-the-street.
Look a monkey!
Believe it or not, Donald Knuth has a paper "The Toilet Paper Problem" in his book Selected Papers on Analysis of Algorithms (ISBN 1575862123).
At the beginning was at.
If you want to make a fast buck, go the the hardware store, buy a bunch of sand-paper, and resell it at a Trekkie convention as Official Klingon Toilet Paper. (You might need to print up some fancy-looking packaging.)
Sells like hot cakes.
I just don't like to be around when they test it on a dare.
Table-ized A.I.
What kind of anal person wastes time on scheduling/queuing algorithms for TP?!?!
It may seem stupid at first, but it could make for an easy introduction to algorithms for young students. Just because it's a somewhat inconsequential topic to everyday life doesn't mean it's not something that's useless.
For example, in my macroeconomics class my freshman year of college, the professor attempted to explain many of the economic concepts in terms of beer and college students. Law of supply and demand: Price of beer goes up, supply of beer goes up, but demand for beer goes down (college students, of course, being limited in budget). Compliments and substitutes: Price of pretzels goes down, demand for beer goes up.
Yes, they are simplified examples, but I firmly believe the only reason I remembered anything from that class to this day is because of the examples she used.
Think For Yourself. Question Authority.
The author discussed, in true binary fashion, "available" vs. "unavailable" for a second roll.
People have also discussed "over the top vs. under the bottom".
There is a middle ground: two rollers, one "over the top" and the other "under the bottom". This would also self-regulate the usage of the rolls, ensuring one ran out before the other.
Which one runs out first depends on the physical characteristics of the holder.
For a fixed holder, the answer is probably "over the top".
But for a hanging holder, where the weight of the paper itself levers the paper into the wall, increasing the overall friction, "under the bottom" allows you to mitigate friction effects, while "over the top" increases them.
Since a fixed holder results in the choice being user preference, that doesn't solve anything; clearly, the fix is in two parts: (1) use hanging holders, and (2) make the primary roll "under the bottom" and the secondary roll "over the top".
Another solution (which is only statistical) is to locate rolls on either side of the toilet. Left handed people are outnumbered by right handed people 20 to 1, on average. But this fix only works "on average", as a result.
All in all, a "P-P complete" problem.
-- Terry
This is one of the textbook examples of what people in several fields (such as economics evolutionary biology) have for some time referred to as "super-rational" behavior.
Th conventional definition of "super-rational" is taking into account the consequences of everyone (or at least the majority) following the strategy. It doesn't actually imply that the actors are rational (or even thinking). One of the topics where it has been used is the biological question of how altruism evolves. The best explanation so far is that a population that behaves altruistically among themselves has a survival advantage over purely individualistic populations.
The double toilet paper example is used as a clear way of illustrating this concept, in a way that doesn't impinge on people's social or religious ideologies. Very few people have any strong feelings about which roll you should use, so they are able to follow the argument without their beliefs causing distraction. And it's clear that a population could behave in a super-rational fashion in this case without being consciously aware that they were doing so. An irrational preference for the inner part of the roll would suffice.
If you ask google about "super-rational", you'll find a number of links to this concept buried among the silly and/or pretentious sites.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
It occurs to me that there *is* a paredo optimal solution.
There has to be.
The problem is "P-P complete".
-- Terry
One can catch the paper against the roller holder and get more friction making tearing easier when the roll is installed "backwords". If you try to do this with a forwards roll you'll have to loop what you've got up and around, which tends to get complicated when one is focussed on the latest issue of Popular Mechanics... or whatever else one might read on the toilet... one-handed.
Oh, I'm sorry, that's for EE majors, not CS people.
/^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i
Perhaps the answer has something to do with whether the paper is dispensed over the top toward the front or over the top toward the back.
This puts in question the author's premise in the first place. He states there are three possible functions for the use of toilet paper.
Algorithm large
Algorithm small
Algorithm random
Perhaps, even before these algorithms are addressed, the directionality of the toilet paper is of ultimate concern.
This is to say that the author's algorithms might be correct if both rolls of toilet paper are equal, but the purpose of the forcing function is to make the rolls of toilet paper unequal.
So I ask: what would happen if, on a dual roll of toilet paper, the closer roll was over the top toward the user and the further roll was over the top and away. This would make the first roll more accessable and therefore might possibly resolve the whole issue.
And I'm not even a computer scientist!
Oh, man. When I read "forcing function," I was going to suggest more fiber, but this is a bit different...
My
Limekiller
(* Hey, no reason that it has to use an external power supply. A micro hydroelectric generator isn't a large thing, *)
Yeah, but that is Yet More Moving Parts to go wrong. Conceptually toilet fillers are simple: The water level pushes up some kind of lever and at a certain point (height) the lever closes the water flow to shut off the refill, stopping all activity. However, there are more things to go wrong than there are parts, it seems. If simple stuff breaks, then a generator and power storage etc. are just gonna make it worse.
Is it gonna look like a car engine under there one of these days?
Table-ized A.I.
(* Origin of the word "crapper": From Thomas Crapper, an Englishman, who developed and manufactured the modern toilet bowl, which was used by US soldiers in World War I and...*)
:-)
The person who told me the story got it all mixed up. The Englishman was named "Thomas Shitthead" in the story I heard
If his name was "Thomas Smith", would we be saying, "You are full of smith!" instead?
Table-ized A.I.
There is more to computer science than mastering the latest buzz words.
All your favorite sites in one place!
If you have a cat, the roll needs to face towards the wall, or you'll find it unrolled and most of your home TPd. On the other hand, my can is now able to unroll it in either direction.
Or a DOS attack.
(ahem. the way God intended.)
> but a sizable minority (myself included) put it in there so unrolls from the bottom. Each group drives the other nuts.
Unrolling from the top makes sense - it's the middle of the night, you take a dump (or leak, if female), and you just wanna paw at the roll (why turn the light on?), and wow, there's a sheet or two or three in your hand.
Or "huh, wheredafuxdapapuh? fuggin underrollin' roommate", and you have to shove the roll away from you until the pieces of TP finally emerge from behind the roll in the wall.
OK, heretic. What's your excuse?
(Actually, the excuse of the other guy who said "under is best because it's easier to re-roll if the cat unrolls it" made sense. But as long as I'm in the company of an under-roller, what if there's no cat in the house? Seriously, what's the rationale for under-rolling?)
"Also, why are the flush mechanisms so fragile? It seems every house and appartment I have ever lived in had problems with the flushing and fill mechanisms."
When was the last time you remember seeing anyone do *preventive* maintenance on a toilet? It's not something people want to think about. So when things don't work quite right we just ignore it or jiggle the handle while it slowly gets worse and worse until it finally breaks.
BTW, I had to fix one a little while ago, and according to a do-it-yourself book, the most common point of failure is in rubber parts (especially the flapper valve) which degrade and must be periodically replaced. You can get more expensive synthetic ones that will last longer, but over time even those can suffer from deformation that will degrade the seal.
I don't know if it's even that inconsequential. Think about all the times you've had to deal with messed-up toilet paper systems in publicly accessible toilets (restaurants, stadiums, theaters, etc.). What if someone were to spend a few weeks determining all the parameters of various toilet paper setups, and producing some kind of definitive work on the subject?
Yeah, I read that and it sounds like I'm joking, but I'm not. Surely there can't be more than one or two "optimal" toilet-paper-dispensing solutions, and it seems bizarre that these were not determined years ago. It doesn't seem like the circumstances surrounding the use of toilet paper could have changed all that much in the last fifty years.
I mean, let's think about it. There's two major categories of toilet paper usage: public (restaurants, stadiums, theaters, amusement parks, businesses, etc.) and private (residences). Obviously, private TPS (Toilet Paper Systems) don't need any of the security features that public systems do.
Let's look at private TPS first. What are our parameters and needs? Well, in most situations, replacement TP rolls are within reaching distance of someone sitting on the toilet, so that's not a problem -- having two rolls doesn't really help that much, because you're STILL going to have to replace the rolls at some point (probably when one expires is the proper algorithmic way). The biggest problem I've noted with private TPS is that the volume of space allocated to the roll tends to be just small enough that a full roll comes into frictional contact with the supporting wall -- so when a roll is fresh or near-fresh, it can be difficult to draw it properly (you tend to get tearing, due to friction). Two solutions to this: 1) Have the axis of the toilet paper out far enough from the supporting surface so that a standard-sized roll will not touch it. 2) Have a depression carved into the supporting surface (usually in the form of a semicylinder) so that the full roll does not protrude too far out from the supporting surface. Ideally, the depression should be large enough so that a standard-sized roll does not touch any part of the inside of the depression. Also note that any holder or support mechanism should allow for significant expansion in the size of toilet paper rolls, since the "standard size" may change (and if it gets smaller, that's not much of a problem, but it's more likely it'll get bigger, and we don't want to have to retrofit our holders later if we can avoid it).
Other factors... the spindle itself should be a single unit, usually a pair of size-offset cylinders attached by a spring. The individual cylinders of the spindle should absolutely NOT be able to come apart (except by violent prying). The spindle's exposed area (i.e. where the roll hangs) should be sufficiently long that a standard-size TP roll can spin freely without being crushed between the arms of the holder.
(Also note that these parameters call for a standard size roll of toilet paper, which would theoretically be specified by shipping dimensions, i.e. diameter and height -- if a company wants to make a single-ply roll and a double-ply roll, the roll should be the same dimensions, meaning that the double-ply roll will have fewer sheets.)
Should the spindle be able to move freely, and spin in the holder, or should it be more or less locked in place (by a physical obstruction, or by friction?), letting the cardboard TP spindle itself rotate around? As long as the TP roll itself has sufficient space inside the cardboard spindle to rotate freely about the support spindle, then the support spindle doesn't need to be able to rotate...
See how much thought can go into just a few aspects of a problem like this? We don't think much about how things like this go, but imagine if you went the rest of your life without ever having to deal with poorly-designed toilet paper mechanisms again. It wouldn't necessarily be something you'd notice, but that would be the point -- a single medium-sized application of brainpower, once, could save millions of people from ever having to think about it.
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
Furthermore, most homes have something nice and pretty called a "under-sink cabinet" in the bathroom, which is where you keep the extra toilet rolls when you have a one-roll holder. It solves the problem of which roll to take paper from (the one in the holder, not the one out of sight in the cabinet, in case you are part of the few percent of the population that doesn't get this). And that is why most homes don't bother with ugly, bulky, industrial-looking dual-roll toilet holders. People who have a separate room for their toilet and no under-sink cabinets usually install a little cabinet in that room, useful not only for holding toilet paper but also cleaning supplies.
Most normal people understand this. Most normal people know to look in the cabinet when they run out of toilet paper. (Most normal people also know not to keep any incriminating or unusual personal items there because they understand that other people will be looking there.)
I think the fact that one of the foremost HCI experts in the countries thinks it worthwhile to share his profound insights on this matter tells you a lot more about the state of HCI research than anything about toilet paper. Apparently, HCI researchers think that the rest of the country consists of idiots who don't even know what to do in the bathroom. In different words, I think a lot of HCI research is roughly at the same level of worrying about installing dual-roll toilet paper holders in the home.
One neglected aspect of this whole discussion is the all important physical placement of the roll holder.
One some toilets I've visited the arrangement fails to acknowledge that the distance to and / or placement of the roll holder relative to the actual toilet seat is an important design parameter.
On some of these poorly designed arrangements the roll is placed almost, but not entirely out of reach forcing one to leave the seat which we all know feels somewhat ackward. Others place the roll holder closely besides or even behind the actual toilet in such a way that you initially panic in search of it and - after discovering it - physically stress your body trying to find a way to get to the roll.
I think there's enough material in these observations for at least another paper on the subject.
naah sig schmig
-3Suns
~~~~
The Revolution will be Slashdotted