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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.
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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.
from the you-know-you're-taking-too-long-in-the-bathroom-wh en department.
slashdot!=valid HTML
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
I would be interested to see statistics on toilet paper use vs. size of the roll. My bet would be that people will use more paper when the roll is full sized compared to when it is smaller due to the number of rotations and time involved to get the same amount of paper. This may be an argument to have a number of small rolls instead or one big one at commercial facilities where toilet paper use is a noticable cost.
Apple only hired guys who knew their crap.
Only in slashdot are posts of solidarity modded at -1 Redundant, while posts of antagonism are modded as -1 Flamebait.
This topic is full of shit!
Table-ized A.I.
...I knew that degree in CS would come in handy some day.
When you run out.. just used a printed out copy of a Microsoft EULA!
Never email donotemail@WeAreSpammers.com
Excellent! This will invalidate the first-grader's rant for a paperless crap session!:
:)
"Be a man, use your hand."
I used to think that I needed to get a life, but heck, this takes the cake.
What kind of anal person wastes time on scheduling/queuing algorithms for TP?!?!
Having said that - I have the chindogu book, and it looks like this guy is _not_ a minority of one. Worrying...
Havng said that the banner you hang from your forehead in order to cover your yawning maw and smultaniously indicate which stop you'd like to get off at when wanting to sleep on the subway train is darned useful.
THL.
Keeping
From the header, I believed this was a news about Lisp...
"player 4 hit player 1 with 0 stroms"
But what about the over/under dichotomy? Most people put the toilet paper in the holder so it unrolls over the top, but a sizable minority (myself included) put it in there so unrolls from the bottom. Each group drives the other nuts.
This should be taken into account somehow when exploring any toilet paper algorithm.
ROFL ya took the words right out of my mouth. For those of you that don't get the obscure reference, Sly Stallone was confused in Demolition Man, after he was un-cryogenically frozen in the future, by the three shells in the bathroom instead of toilet paper. He never did figure it out.
Aw, fuck it. Let's go bowling. - The Big Lebowski
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.
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";
I thought they always told you not to force it.
?-|||-----x<*))))><
He has some interesting common sense solutions to today's problems I wish companies thought like he did
***I GOT NUTHIN***
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
By using a smallest algorithm you get no benefit over random or largest, except for the option of negating the purpose of dual rolls. With smallest you can refill either after one roll is out or after both rolls are out. If you do it after one roll is done, you've lost all benefit of a dual roll setup: you still have to refill after each single roll and because there is no discernable difference between two fully (or nearly) stocked rolls the one you start using will be the one you keep using. The second roll doesn't even get a chance.
If you choose to refill after two rolls you end up with no gain over random or largest since you have to refill two at a time no matter what.
Conclusion: there is no best way to deal with a two roll setup. The advantage conferred is just that you don't have to refill for twice as long if you choose. If you want to refill at the same interval as a single, stick with a single.
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.
"Hi, my name is Don, and I have too much free time on my hands."
Never argue with a man carrying a water buffalo
Just how did the shells work? I never got that.
1 tequila 2 tequila 3 tequila floor
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.
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
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.
Hey, no reason that it has to use an external power supply. A micro hydroelectric generator isn't a large thing, and the water pressure in an average American household has enough energy to produce several hundred watts.
-James
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.
Just how did the shells work? I never got that.
we purchased holder of two rolls, side by side. We discovered that although we now had two rolls instead of one, the problem was not solved.
It's disturbing to see "The Guru of Workable Technology" was unable to identify a correct solution to the problem before he purchased and used the product...
Luckily the "guru" was eventually able to identify and correct the problem, then share the experience with us all! (Don't you think a "guru" would have better things to write about?)
It occurs to me that there *is* a paredo optimal solution.
There has to be.
The problem is "P-P complete".
-- Terry
Do you "double-dip"?
...Also, you can WinToiletPaper.Com
Are you a "perfectionist" or an "inspector"?
Take the Bathroom Habits Study here
(An error occured processing this directive.)
Cover your eyes and click this link!
At my home on campus, they are installing new showers. To do this, they needed to turn off the water. It's been off since Wednesday, and will likely be off until Monday or Tuesday. Talk about disgusting. We've been running out to Wal-Mart and buying gallons of water so we can flush the toilets. It wouldn't be that bad, but one of the guys in the house must have some major problems, because he has to go #2 a lot. And they smell real, real bad.
Toilet paper is the least of concerns.
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 brought the word "crapper" back to America. His biography was entitled "Flushed with Pride".
"I may be quite wrong." - Socrates
At my work they have installed the commercial type where pushing down on the emtpy roll drops the next roll into place.
Alas, invariably the next roll gets dropped into place before the first roll is complete. You end up with two touching rolls, one on to of the other, both of which are hard to turn.
As for the "over or under" question that is not addressed in the article but many people seem to be discussing, most people with cats would prefer the under approach. The over approach is far too easy for my cats to unravel, leading to the bathroom being turned into a toilet paper playhouse while I am away. At least the under approach makes them think a little (something they prefer to avoid).
Life is like a web application. Sometime you need cookies just to get by.
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.
At least it looks as if the toliet paper problem is defintely in P. Human beings could be doomed to a lifetime of misery should the problem had been intractable.
If religous zealots don't believe in Evolution, then why are they so worried about bird flu?
By using a smallest algorithm you get no benefit over random or largest, except for the option of negating the purpose of dual rolls.
I normally don't get into the scatalogical stuff, but the above asumption is wrong for places where the people using the article are not the ones who replace the article.
I work in a place where the men's restroom in the software section (can't vouch for the women's restroom) has 3 stalls, two have the "forcing function" dispensers, and one has the dual roll dispenser.
The "forcing function" dispensers have long since been severely damaged as a result of (I'm assuming) lack of fulfillment during a moment of need.
The rolls in the recently installed "dual roll" stall were initially subject to the algorithm large. Once the sight of two nearly empty rolls greeted the visitors, the popular usage quickly became algorithm small.
I've not wasted a couple hours yet, but the Essays I have read are quite insightful... I'm especially fond of the one titled "in defense of cheating". My wife has her degree in education and is homeschooling my 5 year old son, I'm going to have her read them and give me an educator's perspective on them. I think that the concepts are more intended for a higher education but I'm curious if she will come up with methods for implimenting them into an early childhood classrom. His assertions of attractive things working better and his corresponding defenses are very interesting as well.
wordtrip.com
$a=$rolls[0]; $b=$rolls[1]; if ($a $a) { use Toilet::RollA; } elsif ($a = $b) { int(rand(2)); } if ($a eq 0 && $b eq 0 && $USER{'diarrhea'}) { die "Crap!"; }
Here's a good teamwork exercise/competition for management training classes: Given two adjacent porceline bowls in a restroom of a large building and two rolls of toilet paper, unroll the two rolls or toilet paper completely on parallel paths starting at each toilet, running out the door of the restroom and through the halls of the building. Each team of 5-10 people gets one strand of TP and the corresponding toilet. The team that can flush its roll entirely down its toilet first without severing it wins. This demonstrates that the role of management is (a) coordinating work, (b) moving paper, (c) making people rush, and (d) moving unpleasant pieces of paper rapidly to a place where no one can find them.
Why do they call it a crapper and not a crappee?
Alternatively, there is the squares of newspaper hanging off the nail. Cheaper and you can refill it when it is half used!
I dont care when the paper tube is full or empty,.. I just want to be able to spin it and get my paper.... but the age old conflict is really the hanging direction. I posted a poll about this back in 9/2000 Go Vote!
Oh, I'm sorry, that's for EE majors, not CS people.
/^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i
Assuming that the average time in the restroom is 1 minute for men and five minutes for women. Given that an airplane or restaurant has two toilets. If these are changed from accessible to either sex to sex-distinct, then the average wait for men is reduced about 80% but for women increased about 100%, so it is a net loss. However, if these are changed from sex-distinct to accessible to either sex, then the average wait for men is increased about 400% and for women it is decreased only 50%, so it is also a net loss. The net net result is that nothing can be changed, and the tyranny of the status quo prevails.
Soap. Rinse. Dry. The three seashells? Must be.
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.
With the button called "ATR" for (Automatic Tampon Removal) and a guy who accidentally takes care of business in the women's washroom...
--------
Bleah! Heh heh heh... BLEAH BLEAH!!! Ha ha ha ha...
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.
he doesnt know how to use the sea shells!!
hahahahahaha!
*ahem*
well thats understandable
Gentlemen...BEHOLD!
-Dr. Weird
Or a DOS attack.
Engineers at Cisco Systems have known about this problem for a long time. Being in the field more often then at home, they came up with WRED, weighted random early drop. This method has enabled them to reduce buying toilet paper for their own home use to a very manageable small number of times a year. Clever.
Ex DEC Alpha people -> AMD Hammer engineers
:)
Ex Amiga people -> Newtek, scala, etc..
Ex SGI -> NVIDIA
etc etc..
Ex-Apple -> Toilet paper algo. research.
I rest my case
--- Metamoderating abusive downgraders since my 300th post.
ok, so every non-cat-owner knows that "over the top" is easier to use. Simply make rotating roll holders. Have one roll "over the top" and one the opposite. Then, when the over the top roll runs out (which will almost certainly be sooner than the "under the bottom" roll), simply rotate the under the bottom roll so it's over the top. Then, when the person who used the last of the roll replaces it (and he had better), he must simply place the new roll in an under the bottom orientation.
One needn't force the correct usage. Often making the preferred choice more attractive will suffice.
This is the centre of the problem; all of the other BS (sorry, I just had to play that card; what I meant was overcomplicated speculation) veers off and becomes a bit irrelevant, as the only thing sought is a holder for the next roll of toilet paper. However, it is not to be used until the current roll is empty. What could be simpler than to create a cylindrical container in which to put the next roll? It would be inaccessible for use but ready to bring out and replace the old.
true && more || less
Why bother wearing a toilet roll on your head? Simply take it to it's natural conclusion - Nappies.
Sure, you could always carry a toilet around in your pants, but thats not really practical, is it?
But really, as children, (unless we go by Homer Simpsons method of letting them run around free in the garden and let nature take its course) we wear nappies, (Diapers, whatever)
As senior citizens, embarassing deterioration of our internal organs may drive us to take similar action.
So why in the middle must we train ourselves to go against what we learnt as babies, only to go back to it when elderly?
Add the fact that we sleep for roughly one third of our lives, and during the period of our lives when we aren't in nappies we can usually control our bodily functions to avoid accidents while asleep.
So, in effect, time on/at the toilet makes up a miniscule amount of our lives, yet it takes a lot of time in getting to and from the toilet, not to mention buying and using toilet paper, and washing hands.
Why go through all this bother? Save space in your house! Save time! Save water! Wear a nappy today!
A paid comment brought to you by the Nappy Makers association of Australia
c - a blessed +5 grain of salt
"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.
No offense to Don Norman, but come on, this is stretching it. When the goal is to ensure that one roll of toilet tissue is exhausted before the other, then it seems pretty obvious to me: finish one roll before starting the other. Duh. Anything that uses both is going to increase the likelihood that both run out at the same time.
You don't need to have a computer science degree to figure this out; you just need common sense.
In fact, thinking like a computer scientist might be what caused him incorrectly to consider a random algorithm in the first place.
Hmm. I find this analysis to be metaphorical of the
:-)
American two-party political process. Dispite
Kennedy's famous assertion, people join political
parties not for what they can give the party, but
what the party can give them. Like the toilet paper
dilema we subconsciously choose the "bigger roll",
as it were, because that party has "more" to offer.
We are oblivious to normative rate of decay in the
system because our initial strategy is a subconscious
one.
Write 3000 words on the subject.
Where have you been living? It's no longer called "toilet paper" -- it's now "toilet tissue!" My god, you people are so uncultured it's a wonder you don't spend all your time in front of a computer screen talking to people over some magical worldwide web.
[insert witty comment here]
not
An episode of the old Fox series 'Married with Children' had Al Bundy installing his own bathroon in the basement so he wouldn't have to share with the rest of the family. After going through a quest to find the right crapper, one with the most 'satisfying flush', he proudly mounted 4 TP dispensers on the wall so he would never be without.
I have to admit: I've come up with some pretty decent ideas in the bathroom and to have my thought process jarred by a missing roll of TP would be frustrating.
He never did figure it out.
He did get somebody to explain it in the end. Meanwhile he just used the fines he would have in his hand two seconds after saying any four letter words.
Do you care about the security of your wireless mouse?
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.
"When the roll empties, then what?"
Hire a certified consultant to wipe your butt.
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
for stupid people that store their toilet roll somewhere other than in the toilet.
I mean come on.
New guy in town walks into the bar, and after a few drinks, heads to the toilet.
Looking inside the stall, he sees no toilet paper, only 3 seashells where it should be.
He wanders back and asks the barman what the shells were all about. Barman points and laughs and says 'It's the great new thing, try it out! Just don't press the third seashell!'.
So the guy walks back to the toilet, does his business and presses the first seashell. Quick as a flash, a spigot pops out and cleans and powders his arse.
Guy feels quite impressed. So he tries the second seashell. Quick as a flash, a soft but rather robotic arm seizes his penis and gives him a very enjoyable jerkoff.
Filled with curiousity, the guy can't resist pressing the third shell.
Guy wakes up in hospital in total agony..."What happened he asked"
"You pressed the third seashell didn't you?"
"Er, yeah, was that wrong? What was it?"
"Automatic Tampon Remover"
in my office building, one of the two rolls of paper is 'locked' by a little sticker which urges you to 'help save earth's resources by finishing the first roll first'- it also mentions that it is a patented device.
L
Dev elpizw tipota, dev phoboumai tipota eimai lephteros http://euclidian.org
Here's the best and simplest solution: Leave an extra roll or two on top of the water tank of the toilet.
It's simple and elagent.
Surely there can't be more than one or two "optimal" toilet-paper-dispensing solutions
Along those lines, I've wondered why urinal design hasn't converged on an optimal solution. It seems there's a new configuration every couple of years, yet the problems of back- and sidesplash have never been satisfactorily addressed.
Oh well, I guess that's what shoe polish is for.
-3Suns
~~~~
The Revolution will be Slashdotted
TOILET PAPER METH? I have never understand that. Toilet paper is for wiping. Math is for comprehensive.
Bad Cops