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Scientifically, You Are Likely In the Slowest Line
MojoKid writes "As you wait in the checkout line for the holidays, your observation is most likely correct. That other line is moving faster than yours. That's what Bill Hammack (the Engineer Guy), from the Department of Chemical and Biomolecular Engineering at the University of Illinois — Urbana proves in this video. Ironically, the most efficient set-up is to have one line feed into several cashiers. This is because if any one line slows because of an issue, the entry queue continues to have customers reach check-out optimally. However, this is also perceived by customers as the least efficient, psychologically."
Please, please, someone forward this to Jim Sinegal.
That ain't liver; that's beef kidney!
That, or it's a more efficient use of space to have displays and inventory running down the center of the store, rather than a huge empty lane leading into a tree of registers.
I thought we've verify the efficiency of single line queue for many years.
I only see that done at banks, DMV's, and Fry's.
Lots of locations in the US have discovered this. Fry's, REI, and just about any bank or credit union, to name a few.
I noticed they did this at fry's. Probably for this reason alone.
Non impediti ratione cogitationus.
See, you have three checkout lines to choose from. You can't see the register from where you are, but at two of the three lines the cashier is a goat...
What this has to do with science?
That's a shame, since it's obviously the most fair, and eliminates the annoyance of jockeying into different lines to maybe get a faster one. I guess people like the chance of getting lucky occasionally, even at the cost of utility (average wait time) and fairness? Hmmm, our economy makes so much more sense now.
At Fry's, you know the line is moving fast because you hardly ever stand still, especially on Black Friday.
One thing Fry's does that most other single-queue places don't do is they "hide the lines" - you can't see the cash registers until you are almost to the head of the line.
Disclaimer: I am a former Fry's employee who shopped there long before working there and still shop there today. Other than that I have no vested interest in Fry's Electronics.
How is that ironic? Doesn't everyone know that? There is no customer configuration in which a single queue isn't more efficient than multiple queues, in average or worst-case waiting time or throughput. You could probably model that and prove it mathematically without needing simulation or experiments.
I always thought the one line/multiple cashiers was the most efficient, that way you don't have a single point of failure.
Before this became popular, every time I went to the Best Buy checkout was the exact time somebody wanted to argue over the fucking extended warranty on their $50 DVD player.
I rather like the self service lines. Maybe it's just me but the baggers always put my squish ables in with my canned goods it seems like.
Woot! Microcenter in my area has this ... though these days it still has long lines due to inefficiency of the security locker for small & high value products being purchased by newbies.
Still the last good place in my area to sell good and sometime hard to find odd toys & parts locally. The impulse buy at the the single queue is harder to resist though.
Santa Baby, a Fryes in my state Please!
... the whole thing could move about twice as fast if people wouldn't:
* Pay with a check
* ... and not even start making it out until the cashier has already rung up the entire bill.
* Wait until the entire transaction has been calculated before presenting coupons, making the cashier start again from scratch.
* Stand around after their transaction is finished fiddling with lord knows what, but delaying the start of the next transaction because they're still in front of the machine where the next person has to swipe their credit card.
* Yak with the cashier after their transaction is done. If you want to make smalltalk, please don't do it when there are 20 people queued behind you.
* Quibbling about a $0.10 difference in the price of some item, making the cashier suspend processing their items in order to check on something.
* Suddenly remember three more things they need, again suspending the proceedings until someone runs back to obtain them.
* Using their time in front of the cashier as opportunity to button their kids' coats and put their gloves on, as if they can't do that *elsewhere* before departing the store.
And so on. I'll take suboptimal queuing algorithms plus smarter people over an optimal queuing algorithm and dumber people any day. But that doesn't appear to be a choice :-/.
outside at the drive-up ATM? this is maddening! I have 3 ATMs at my local BoA and I try to wait for the next one to become available, but most times I'm forced to pick one at random (of course the slowest) because some asshat behind me lays into his horn until I do
Watching the video, the conclusion that the video makes is "...You are likely not in the fastest line".
That does not necessarily mean that the reverse (the title) is true -- and yet they somehow jump to that conclusion with the title "...You are likely in the slowest Line."
Can we get some people who actually understand this magical thing called "logic" to start editing Slashdot?
AccountKiller
I tried positioning myself between two queues at the checkouts of my local supermarket to try to merge the lines, someone behind me asked which line I was in and when I replied "both" they sure did give me the stink eye. People just don't want to act in their own best interests.
Nullius in verba
The video actually says that, mathematically, you are likely (2 out of 3 times) not to be in the fastest line.
In his example of three lines, there is still a 2/3 chance that you are not in the slowest line. So unless "one in three" has become "likely," the headline demonstrates a failure at basic maths.
Finally! I love the idea and I thought this should be done for all lanes since I first stood in line for a self checkout machine. Sure the queue looks long but the checkout speed is optimized. Supermarkets, certain retailers and home improvement centers frequently feature self checkout lanes that are fed by a single line. Even if a person has a hard time using the machine, you are pretty much guaranteed the others are speedily checking out and will be done in minutes.
I have always thought it stupid that many retail chains have a dozen or more checkout lanes with a large front aisle clogged with carts and people. There should be one large queue from one end of the building to the other and the checkout lanes should be arranged in a circular or star like shape so the center is where the queue terminates. The queue can be fed from the main aisle and feature benches on one side and racks of last minute crap like magazines, candy and the like. This eliminates the god awful clogged front aisle. It also guarantees you wont get stuck on line behind someone with 100 items and a slow cashier.
Ironically, the most efficient set-up is to have one line feed into several cashiers
How is that ironic? It strikes me as mind-numbingly obvious.
What's this mean? Two thirds of the time at least one neighboring line will be moving faster than you, and you'll curse and stew and froth about your terrible misfortune. But look on the bright side -- two times out of three, at least one of the neighboring queues will have exactly the same burning jealousy towards your swifter, more efficient checkout.
Ironically, the most efficient set-up is to have one line feed into several cashiers.
Alanis Morissette called; she wants her misused word back. Anyway...the above statement ain't necessarily so. What putting everyone into a single queue does is ensure that the distribution of waiting times is very narrow -- everyone will spend very nearly the same amount of time in the queue before reaching a cashier. However, this setup will almost always impair overall checkout efficiency (measured in customers per hour) by some amount; the average waiting time will be slightly longer. Each time a customer clears the cash desk and the cashier has to wait for the next customer to arrive, time is lost. Since the customer can't unpack his basket while the cashier is finishing with the previous customer, time is lost. It gets worse if a customer at the head of the queue doesn't realize that a cashier is available; everyone stands around waiting that extra bit of time. Yes, this can be offset by having a staff member playing shepherd, but that's extra expense for the store (and wouldn't it be better to have that employee actually manning a cash register?). As well, the store needs to be able to maintain a larger open space by the cash registers through which people can move, to get from the head of the queue to the checkout.
In other words, the one-queue system is less efficient in terms of staff costs, less efficient in terms of average customer waiting time, and less efficient in terms of use of floor space. The only advantage is the one alluded to -- it eliminates the slow cashier/slow customer/bad luck penalty, and ensures that everyone has roughly the same wait. (And for that, I actually do prefer this system -- but I don't pretend that it's really more effiicient. I accept that I'm paying a small premium in average waiting time - and writing off a chance to ever be in a lucky fast line - to avoid the risk of occasional long waits.)
~Idarubicin
He's correct that in theory a single queue is most efficient overall, however, that doesn't scale well beyond about 8 registers. Fry's Electronics is a great example. The time it takes to walk from the queue to the specific register that is open is wasted time. So, when there are many registers, multiple queues that feed each bank of registers are more efficient. To make that optimal, or nearly optimal, you can start with one line, and split it as many times as needed to have people ready and waiting near each of multiple clusters of registers. There should be at least 4 registers per cluster to minimize the impact of a delay, and no more registers than can be accessed quickly from each queue outlet, which is typically no more than 8 registers. This is similar to the system used at ski lifts. There are multiple lines, including a "singles" line that gets as many people as practical on each chair.
BTW, Best Buy uses a single line setup, at least during busy shopping periods, so it's not just Fry's, banks, and DMV.
make imaginary.friends COUNT=100 VISIBLE=false
I wonder if it has anything to do with the large blood stained machette that I carry when I go shopping ... :-)
A line chosen at random from n lines has a 1/n chance of being the slowest. Consequently, except when there is only one line, you are not "likely" to be in the slowest line. When there is only one line, the slowest line is also the fastest one. When there are 2 lines, you have even odds of having selected the slowest line. When there are several, you are just as unlikely to have selected the slowest one as you are to have selected the fastest one.
FIRST... no he dose not prove that you are in the SLOWEST line. He demonstrates that it's most likely that you are NOT IN THE FASTEST LINE. The exact same argument can be used to show that you are likely NOT IN THE SLOWEST line [of course, Slashdot editors and readers have never written any kind of mathematical proof, so the concept of "similarly" is foreign to them].
SECOND... this is elementary probability... barely even high-school level.
Given 3 lines
WLOG, randomly choose one
there is 1/3 probability that your line is the fastest
therefore there is 2/3 probability that your line is not fastest
therefore it is more likely that you are not in the fastest line
THIRD... there is nothing ironic about the single queue being fastest. This is obvious to anyone who has even set next to someone who's brother's dog licked someone who accidentally clicked on the wiki page for queuing theory.
I cannot believe that this drivel got posted. Apparently, Slashdot is now for remedial math. AND the poster (and editors) didn't even get it right! Slashdot editors fail remedial math.
I know this site went to shit about 7 or 8 years ago, but all nerd cred is forever lost in my eyes. It is now just for 12 year old mouth breathers who have no idea what they are talking about.
Logging into my account that I created when I officially gave up on this website. I am not going back to routing *.slashdot.org to 0.0.0.0 so that I am never tempted to return here on a lark.
but noooo those douches try to cut everyone off and try to cut in line, thus slowing the entire process.
If you have 3 lines, you'd think that 2/3rds of the time there's another line which moves faster. But if you're in a slower line, you're spending more time in that line. So with three lines, you're only in the fastest line for 1/3rd of your purchases. But you're in the fastest line less than 1/3rd of the time. The way Fry's does it with a single queue is pretty much the best way (I can think of an exception for those 10 items or fewer lines).
We always knew that throughput and response time do not agree. but what about having a display at the EFTPOS displaying customer clearance rate for every single line? In that way customers can perceive themselves as making an informed decision as to which queue they want to be cleared in, while more efficient queues can in fact get more of the workload. And since the customer made the active choice which queue he/she wants to be in, they will feel more personally responsible for whatever speed the queue is moving at.
I used to get yelled at almost weekly at Trader joes, where they have space for a single line to feed 2 stations. I did the math and realized, yeah, waiting for either station is faster for everyone involved than picking one at hoping it's the fast one. Every week someone would ask, "Which line are you waiting for?" "Both of them, whichever opens first." They hated that. "You can't take up two stations!?!?" "I'm not, I'm taking up the first free one, otherwise we're just gambling on which one is faster, and given that I've been standing here longer I probably know which one, though the inept lady with her credit card at the bottom of a cavernous purse could be a game changer." Ugh, my fellow Americans.
Certainly it's unlikely that you are in the slowest, but as the video the article embeds points out, it's certainly likely that some line is faster than the one you chose to find yourself (when N>2).
However, they don't get into the other issue which is if you should switch or not (probably not if all lines are approximatly the same length statistically speaking)..
In An Introduction to Probability Theory and Its Applications by William Feller, published before 1968, Feller describes this effect, pointing out that we mentally average over time, not occurrences, and spend most of our time in the slow line.
between single-line multi-server queue and multiple queues.
This occurs in fast food restaurants with the row of cashiers.
This is because some people are "blind" to the fact that there is a single line
situation in effect. These people can be divided into:
1. The generally oblivious. Mindless automatons or cellphone talkers.
2. The socially clueless. Somewhere on the autism spectrum, they don't
understand that queuing is a complex social interaction with rules and etiquette.
3. The obnoxious. Sees the situation but overtly butts in front to stand in front
of one of the cashiers directly, thus forcing others to break rank and sneak in
behind him, since the discipline is shot.
4. The "will be first up against the wall when the revolution comes" devious, who
form their own line like #3 but do it by carefully assessing the situation then actively
pretending that they are in category 1.
So it goes to multiple queues for a while, then some opportunist realizes they
can line up ambiguously in between two cashiers to snag whichever comes open
first, and we're back to single-line til a type 1 to 4 person arrives.
Where are we going and why are we in a handbasket?
Nothing ironic about it; but it's so amazingly impersonal.
Walmart has lines like that at a location near me; it's always filled with trailer trash rednecks.
Because real nerds were all required to write a program to demonstrate this in their first CS class.
I believe there's also a throughput bonus from societal pressures - you're less likely to take time bagging, fiddling with your wallet, etcetera when you notice ten people standing behind you. This is being adopted more and more in the UK through self-service stations in supermarkets.
I could be the first person ever to be modded up for saying "Best Buy FTW!!!"
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)
Honest question... I'd really like to know. I've *always* seen the single line feeding into multiple cashiers as going far faster, on average.
File under 'M' for 'Manic ranting'
MOST of the stores I go to have single-line queueing, supermarkets being a conspicuous exception. Usually it's done by setting up rope barriers on stands, with a "line starts here" sign.
TSA security and airline check-in work with a single queue. Walt Disney World has been operating that way literally for decades.
And MOST of the places that don't, almost do: clerks at McDonald's, CVS, etc. are trained to say "I can help whoever's next" as soon as they are free, which has much the same effect.
"How to Do Nothing," kids activities, back in print!
"Right now, there're hundreds of
different languages being spoken around the world - you think one more is going to destroy communication forever?"
Where are we going and why are we in a handbasket?
The poor register jockeys making a flat hourly rate no matter how many customers get through their lines. The harder they work, the more work they make for themselves, particularly if they're sharing all the customers. (Anyone who's worked in any sort of real job surrounded by slackers knows this.) At least with your own customer queue, you can kind of see an incentive to get them all through, even if more keep showing up. As an added bonus, a manager might notice the ten people waiting to get through the lazy bitch's line (although in my experience, that just results in the efficient one being told he's "not taking initiative" or some similar bullshit.)
MSIE: The world's most standards-complaint web browser.
That 2 out of 3 times - I'm in a faster line than you. Ha!
Also, 6 out of 8 times, my cashier is more competent and better looking.
Mit der Dummheit kämpfen Götter selbst vergebens
Seriously?? The general public (psychologically) feels that a single queue for all registers is the least efficient?? OMG I know it's the most efficient without even having to think about how logical it is. Before I stopped to think about it, I already knew.
It's the most FAIR. The next person gets the next available register. So someone who enters the queue after you will never get served before you, as they would if individual registers had their own lines.
I grew up enjoying the challenge of picking the fastest line.. or not. Even better when friends are competing.
Of course.. here in Canada it's less likely someone will skip the line and cheat the 'game'.
The Fry's line isn't bad... quite efficient... but at some point I begin to feel like I'm in some machine to be fleeced....
With single-line, there is usually some sort of winding chicane/fencing, so during quiet times, it's a much longer winding convoluted walk to the cashier, than a multi-line set up where you would just be able to walk directly to the cashier.
On average, and entirely unsurprisingly, one time in three you'll be in the fastest line; one time in three, you'll be in the slowest line. (And in the remaining third of cases, you'll fall in the middle.)
Don't give me any of that "It's how you play the game" positivist commie-pinko crap.
*I* must win, and everyone else MUST lose. Regardless if it is fastest cashier line or thermonuclear war.
Any other solution is simply unacceptable injustice and it makes baby Jesus cry.
Mit der Dummheit kämpfen Götter selbst vergebens
What if you're in India and there's no line at all? Just a huge mass of people crowding against the service counter shouting for what they want, over and over till the clerk serves them. All while more people are pushing and shoving and yelling...
As an American, used to neat, orderly queues, waiting to make eye contact with the clerk, I end up waiting a long, long time...
Or at some of the big department stores there... Each checkout has a separate line going to cashier, but once you're finished, your goods are in bags and you've paid, the exit isn't ahead, you then have to turn around and go back through the line to exit at the same entrance, all while people in the line are pushing and shoving and trying to cut in front of one another...
I'm sure glad I'm back in the U.S. again this year...
With a single queue that splits up, the time a cashier waits between customers increases, as there is no customer waiting right behind the one currently checking out. The next customer has to actually notice the idle person. Idle cashier time reduces throughput for a given number of cashiers.
The problem most people see with a single queue is that the line is LONG. Our minds have issues thinking of the fact that 4 lines with 4 people waiting each is the same as one line with 16 people waiting. We also give up the illusion of choice with the longer line. With multiple lines, we
can look at the quantity of products in the baskets, the perceived speed of the cashier, if there's a second employee at that register helping to bag groceries, etc. Of course, none of that matters if one of the people you're stuck behind is trying to pay with food stamps and has selected the wrong size of product, and needs to run back quickly to exchange it with the correct size.... or if someone's check won't read, or whatnot.
The other issue with a longer line is that you need space for it. Fry's is set up to handle the long queues, but look how much space that whole arrangement takes up, not to mention the fact that people at fry's don't tend to purchase 100 small items, which fascilitate the need for a conveyor belt and bagging system. The grocery store probably couldn't get away with much less space for the registers than they're already using, so providing space for a long queue would require them to take in more of the store for that purpose. Best they can do easily is provide the express lanes (which would work even faster if they only accepted cash).
-Restil
Play with my webcams and lights here
The Post Office & the Bank lines work this way (where I live), and nobody seems to complain that it feels slower. I think if supermarkets designed for it, it wouldn't take long for (most) people to be accept it.
USPS does indeed have a one line multiple clerks system, but many people come in without their stuff actually ready to mail.
I pointedly avoid doing this and analogous things at other retail locations.
If there is one line and multiple clerks, sometimes the multiple isn't high enough. :P
I listen to both RIAA and non-RIAA stuff if I like the music, tangential business/politics nonwithstanding.
What if you're in India and there's no line at all?
This would have been the first post, but I was on the slowest connection.
This is the same reasoning I read in Roger Highfield's The Physics of Christmas. Good book, I read it every year around this time.
We learned that the single line with multiple cashiers is the most efficient queuing method in my MBA program a decade ago. Not exactly anything new.
i pick the line with fewest women in them because they always seem to want to write a check and don't start pulling the checkbook out of their purses until after all items have been scanned... don't want to be sexist but there it is
... if your goal is to get in the line served by the hottest clerk.
Invariably, some guy ahead of you will tie her check-out up taking a long time digging change out of his pocket (There's really change in there, right?).
Have gnu, will travel.
I bet that the optimal setup, for throughput, would a hybrid of the one line/multiple line strategy.
What about one main line but each of the registers there is a 'on deck circle' for one customer to unload while the cashier is dealing with the first customer. This way the cashier is always dealing with a customer and never waiting for them to get to the register from the single line. Sure, one person could be delayed but that is much better than a whole line being delayed.
A further refinement would be "register groups". Say a store had 12 registers. Making one line for all 12 is inefficient as the walk from the front of the line to an open register could be a long one. Instead split the registers into 3 groups each with 4 registers. Shorter walk times but still benefits from the single line.
The psychological reason for preferring multiple lines is simple to explain. When one comes up on a single line one automatically estimates the time in line from past experience. Since most stores use multiple lines one's calculations will be based on that and the wait time will be greatly overestimated causing anxiety. Some stores try to decrease this issue by having a series of signs that estimate how long the wait will be. The issue is that most people do not believe the signs.
And on a final note; when there is a single line, one is always in the fastest line; one is also always in the slowest line.
Walk on out. They can't stop you.
Maybe not but they've probably recorded every move you've made since you entered the parking lot and they can put you on their "undesirable customer" list if they have one.
I don't know if Fry's has such a list but some stores will go so far as to issue a blanket state- or nation-wide "no trespassing order" to undesirable customers. I don't know if national orders are enforceable but in some states statewide orders work if the affected stores are all corporate or owned by the same franchisee.
Now, they have to have some semi-legitimate-sounding business reason, it can't be just because the manager doesn't like you.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
More people go through the fast line, so you are more likely to be in a fast line than a slow one. You are also more likely to wait longer the times you are in the slow one. And on average, you will wait an average amount of time. Of course if there are many lines chances are there is at least one faster one.
Other than side effects, a single feeder line won't change the average waiting time. But it will make the first people to get in line get to the register first, which matches one way of looking at fairness, and also it optimizes the maximum wait time.
The problem with the one line idea is that stores will invariably understaff the checkout counters to save money. Your lost time is irrelevant to them (See: "Voice Mail Hell"). Thus, the odds of more than one issue creating delays at most or all of the pathetically low number of open cashier stations ensures that everybody suffers. With multiple lines, there's at least a chance that people in one or two lines might luck out.
I've calculated my velocity with such exquisite precision that I have no idea where I am.
its true that the statement of the video doesn't logically match the statement in the title. however, i think the video also makes an error.
the video says, basically, that before you enter a line you have equal chances of picking the fastest line and the slowest line, and any line in between. what it misses is that once you're actually in line, things change because of length bias. if you're in the fastest line, you spend the least amount of time in line; if you're in the slowest, you spend the most. proportionally you spend the most amount of time in slowest line; and given that you're in a line, the odds are best that you're in the slowest one. it boils down to what you condition on - are you choosing the line, or have you already made your choice?
either way though, i'm not sure the concept needs a video to explain it.
Don't we all learn in school why 1 line is faster? I sure did. Not to mention that any place where it really matters (e.g. airports) do this already. Who cares what a handful of people who didn't pay attention in school "feel" about it "psychologically". What about me? Do you have any idea how distressed I get when there's multiple lines to choose from? And no way to know for sure which line performs best?
Let's say I spend some number of hours a year in lines. Statistically speaking, any given minute of my wait is more likely to be in a slower line - since by definition they'll occupy a greater percentage of my waiting time than being in the faster lines.
While we're on the subject, I notice further down people commenting on the new self service check outs that many retailers are starting to put in. They seem to like them. I LOATHE them. In my area, only Canadian Tire and Wal-Mart use them and I avoid them. Certain days through the week, at Canadian Tire only the customer service desk and the self serve checkouts are staffed. I always go to the customer service desk when that happens.
1) The self serve check outs are bar code and scale based. The system has to know the precise weight of every bar coded item. If you don't put the item on the scales, it won't let you continue, yet the scales are imprecise enough that a two back of automotive bulbs often don't weight enough to register. And good luck trying to deal with an unwieldy item that doesn't fit in a standard bag. A regular clerk just throws a sticker on it and moves on. This self service system halts and you have to wait for the central cashier to come over and fix it. This always takes a lot longer than having a clerk already standing there and eager to get to the next customer.
2) The system does not provide a customer a way to manual type in a barcode number the way a skilled clerk can when the bars themselves aren't legible to the laser. At the Walmart, deli items get a custom bar code printed up right then and there, but for some reason, the ink sometimes gets a tad smeared. (I don't know what ink/printing system is in the one they use here.) A human can read the numbers, but the laser can't apparently make heads or tails of the bars. Again, you need that central cash person to come over and fix it.
3) Both self service systems are set up so one person is supervising 4 registers and it seems at least at the Canadian Tire, the management only allots one person to do this per shift. At the Walmart, it appears that during slack time, the customer service person covers it in addition to their other duties. These leads to a problem. If you have four clerks and things are slow, you have the flexibility to send one or two off on break earlier or go stock shelves or something. When it's only one person, sure it's cheaper, but what happens when that person needs to go take a leak? At both Walmart and Canadian Tire on at least one occasion each, there hasn't been anyone standing on that little raised platform next to the self serve checkouts. At the Walmart at least, there was usually two other cashiers on duty. (one at the one queue into multiple registers section and one in the traditional single queue area) At Canadian Tire on the other hand, one time there was nobody, I mean nobody at any of the registers, including the customer service. I looked around, waited a bit and then the customer service staff came back with an empty cart (had been restocking returns I guess) and the self serve supervisor came hustling over from the bathroom/service centre area looking flustered.
I need a wheelchair van for my son. Help me get the word out. https://www.gofundme.com/wheelchair-van-for-jj
That's why you need someone to open up shortcut routes during quiet periods. I believe they do this at some airports.
Also, you can do it in a slightly more subtle way by having markings on the floor and by doing sort of 'nudge'-style design that basically encourages people to form a queue even though there isn't actual physical barriers.
For instance, at some ATMs I use in London, they have big blue arrows on the ground to show people to queue. During busy periods, it nudges people into an efficient queuing protocol, but during quiet times, it doesn't force people to walk long distances.
catch (HumourFailureException e) { e.user.send("You, sir, are a humourless idiot."); }
What the fucking fuck? "There are three groups of two permutations of three variables, two out of six times 'your' variable is the first"
The video is wrong, stupid and stupid. I could say You are least likely to be eaten by raptors if you choose Nike shoes over Adidas and store brand by this methodology...
. Ironically, the most efficient set-up is to have one line feed into several cashiers.
Since irony indicates a result the opposite of what you'd expect, and logic tells us that the one-line option is the most efficient... how's it ironic?
As a CUSTOMER, I strongly prefer a single-queue system. The few stores I know where this is in place feel far more efficient to me at the checkout line than those who do not.
As to the self-checkout lanes; I don't mind them at the grocery store where most of them items fit in bags and the UPC codes are well managed. Where I hate them is places like big-box hardware stores. I once heard an interview with a big wig at Home Depot, where I claimed that the self-check lanes would allow them to put more people on the floor to help customers. It was so much bull that I couldn't believe it he'd said it. There are no more people there and the ones that are are no more helpful. The self check lanes have one purpose - saving money. Less employees means less benefits. A hardware store is the last place (other than a plan nursery I guess) where I'd expect self-service scanners to be at all useful. Also, in a place like that, how hard would be it be to play the "weighs the same as" game? Find a couple of items with similar weights and sizes but vastly different prices, buy one of the cheap ones and take it home. Make self stick on labels with the UPC code of that cheap item. Use the stickers to cover the upc code of the expensive item. Scan, pay, profit. A human cashier would probably catch that.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
Mathematics is counter-intuitive and all humans most of the time do need "remedial math". In addition, there are so many branches of "math" today that even having obtained a Math Dept degree some 10 years ago doesn't guarantee you'd still remember the basics of say probability theory (a *very* counter-intuitive one). Having an IT-related degree or even being a C# programmer also does not guarantee that you would approach at first sight an everyday life problem like the formation of queues in a relevant or correct way. Therefore, I expect a lot of noise in ./ comments and frankly, I like noise, mainly because I am a lonely guy and I have the perversion to enjoy observing knowledgeable people's reactions to the "obvious". Noise to me is study worthy and keeps me busy on long winter nights. All pure signals, proper theorems and clever corollaries render life much less worth pursuing and would collapse ./ into 'true' and 'false' twits.
Your approach is that this post is a "drivel" and therefore "this site went to shit". Could you please also express your opinion on the TFA and video?
What you could accuse the /. poster and editor is that they fail to make explicit what makes this video worth of our precious attention. IMHO, the commentary should make mention of a) the counter intuitive nature of probability b) the interdisciplinary application field of queuing theory and c) the elusive connection between abstract mathematical theories to situations of everyday life. The video excels in all three aspects and was really insightful and informative, especially given that its target audience is not the seasoned mathematician, but Joe Six pack who hates Christmas shopping precisely because of the perceived long queues. Therefore, I'd add: d) a very concise, clear and effective example of popularization of science using elementary tools (looks like the visualizations were made with Impress or Powerpoint).
This story is junk science. First he's using the word efficient incorrectly. As long as all the cashiers are processing customers then efficiency would be the same. To put it another way, the output is exactly the same on average under either system, i.e. the average time spent in line is unchanged under the 1 huge line scenario.
If this is about fairness, then he's right. But a totally fair system means that you can't get in and out quickly even if you try, which means it sucks.
A more efficient system from a human standpoint would have multiple lines. How can I say that? Those that are in a rush will look for the shortest line and get in and out quickly. Those that don't care will get into any line. And those that want to flirt with the cashier will even take the longest line, which leaves the fastest line for you.
What this articles does prove is that you can make a video and still be wrong. But then again people that dislike Fox News and Al Gore already knew that. :)
This story uses the word efficient incorrectly. As long as all the cashiers are processing customers then efficiency would be the same. To put it another way, the output is exactly the same on average under either system, i.e. the average time spent in line is unchanged under the 1 huge line scenario.
If this is about fairness, then he's right. But a totally fair system means that you can't get in and out quickly even if you try, which means it sucks.
A more efficient system from a human standpoint would have multiple lines. How can I say that? Those that are in a rush will look for the shortest line and get in and out quickly. Those that don't care will get into any line. And those that want to flirt with the cashier will even take the longest line, which leaves the fastest line for you.
What this articles does prove is that you can make a video and still be wrong. But then again people that dislike Fox News and Al Gore already knew that. :)
One of our local supermarket stores has recently started using a self service checkout system.
It's absolutely brilliant:
As you enter the store you get one of the many hand scanners by simply scanning your store bonus card. Then as you get all your products you scan each one as you go. At the end you simply place your scanner back in one of the holders and scan your bonus card again and you're ready to pay and after that you're done. Even with the xmas crowd there where no lines for the self service checkout.
Yet still quite a lot of people choose to stand in line... actually one of my friends was in line as I arrived at the store and I finished shopping before it was his turn at the cashier =)
This story uses the word efficient incorrectly. As long as all the cashiers are processing customers then efficiency would be the same. To put it another way, the average time spent in line is unchanged under the 1 huge line scenario.
If this is about fairness, then he's right. But a totally fair system means that you can't get in and out quickly even if you try, which means it sucks.
A more efficient system from a human standpoint would have multiple lines. How can I say that? Those that are in a rush will look for the shortest line and get in and out quickly. Those that don't care will get into any line. And those that want to flirt with the cashier will even take the longest line, which leaves the fastest line for you.
What this articles does prove is that you can make a video and still be wrong. But then again people that dislike Fox News and Al Gore already knew that. :)
but noooo those douches try to cut everyone off and try to cut in line, thus slowing the entire process.
Your time with your kids isn't as important to me as my time with my wii. By cutting everyone off, I get through quicker. Thank you for meekly sitting idle.
What's worse, is your whining rant is marked up as "insightful" - I think that speaks volumes more about the tone of slashdot discourse than the useless article, even if it is primary school level drivel.
Really, do you have so much time on your hands and so much splenetic rage that you feel compelled to tell us in such eloquent depth how you really feel about TFA? Here's a clue, Jack : just close the tab, will you, and get on with your seasonal festivities - you'll be calmer reading something more at your level, all those who failed high school math will be none the wiser and therefore happier in their blissful ignorance of their ignorance, and the planet will keep on spinning.
Burn one down, buddy, it'll do you good.
scientifically in the slowest line likely are you?
Sweet mocha Jesus, we're your parents killed in a tragic queueing mishap?
is an essay written by Donald Norman, you can read it here: http://www.jnd.org/dn.mss/the_psychology_of_waiting_lines.html
He argues that there are several things that matter more; one that matters the most is the perceived fairness of the queue.
It doesn't matter if the line is long, or that you have to wait slightly longer; what matters is that everybody waits roughly the same amount of time, and there is no way to cheat in such a system.
Giving up control is a feature. When you have options to choose from, there is a chance that you made a sub-optimal choice. In the case of a single line - you are certain you chose the fastest option ;-)
The highlight of the paper is that in the context of customer satisfaction, perceivedPerformance > actualPerformance.Whether this rule is the same when it comes to counting the profit - is another matter.
The saddest poem
I made the mistake of going in Tesco yesterday at lunchtime and it was jam packed with Christmas shoppers. So I bought a few things and went in the "express", "self service" line. These lines are served by automated systems which I swear have been designed to a) ignore your keypresses b) ignore barcodes, c) throw up random errors d) randomly say "unexpected item in the bagging area" and generally do everything to neither be express nor self service. Tesco presumably because they need half as many people to operate them but god are they frustrating.
I love that people are out there figuring this stuff out, aids, cancer, queues
http://www.awfullybigmoustache.com
I wonder if it's like Capitalism vs Communism
Capitalism - Sometimes you win, sometimes you lose, but it's ultimately relative to your skill at line selection
Communism - fairness/equality for all.. everyone gets the same
I'm amazed this story didn't get a bad (or rather just plain WRONG) summary tag yet.
You're not likely in the slowest line, but rather you're likely not in the fastest one (well, duh - with N lines you've only got a 1/N probability of being in the fastest one).
FWIW, your probability of being in the single slowest line is just the same, 1/N, IOW you're most likely *NOT* in the slowest line.
When I saw it at MicroCenter, I hated the long line, but it moved so fast, that I have quit carping about it. Basically, it is parallelism the way that it should be done: not at the time of choosing which line, but of choosing which cashier. There is a difference.
I prefer the "u" in honour as it seems to be missing these days.
It's completely obvious that the single line is the best solution. But I've run in to places that INSIST you break up the lines to make one per cashier. WHY? I don't want to stand in front of a cashier until I know they're ready for me.
The reality is that in multiple lines, in a medium load, it is not uncommon to see cashier's lines empty and a cashier WAITING for a customer. Normally, it is less than 1 minute, BUT, they could have checked out somebody during that time.
under heavy loads, you WILL have the same efficiency, BUT, ALL of the lines will be going slower as well due to hitting issues (long queue means higher chance of hitting issues which slows it down).
A single queue is easy to optimize, and keep it optimized, as well as fair under ALL CONDITIONS. A multiple queue will be optimized BUT considered unfair by most customers, under a heavy load. At all other times, it would actually be under optimized. The fact that you spoke of getting into short lines says that. And as to flirting with a cashier, you can still do that with a single line. Heck, you can allow others to go in front so that you get a particular register.
Finally, disregarding your being incorrect about efficiencies on this, if a word is used incorrectly, it does NOT make it junk science. It means that an article was poorly written. But hey, that means that you love Faux News and Al Gore, right?
I prefer the "u" in honour as it seems to be missing these days.
Seriously. Did this need to be studied? I can telly you from first hand experience I am always in the slows check out lane.
Seriously the one-queue idea sounded like the most "fair" set-up rather than the most "efficient" one to me. Sure, if your line's serving some pesky customer you've got a while to wait, but the other lines are still processing customers as usual, so the overall system efficiency isn't hampered much by your misfortune. What's more, you save the overhead of identifying and moving to the free cashier when you're in the queue head. I don't have a study to back me up, but it seems to me that multi-queue is less fair but probably more efficient when you've got lots of cashiers.
PS. "That other line is moving faster than yours" almost sound as if my line is moving the slowest, which isn't true from TFA. Just that my line's not the fastest doesn't make me feel that bad, it's probably not the slowest as well.
Surely this is just proof of gravity and relativity. The more persons in a queue with full trolleys the slower time moves for them due to the gravitational distortion of the trolleys and shopping mass?
when not using the self-checkout at my local kroger's, it's usually because I have a lot of small items. If i just have a few, I scan each item and choose skip bagging, and just put it in the buggy. the platform where you put the groceries will freak out if you even breathe on it. I will get in a longer line if it is for my favored cashiers, because I know they're competent and swift. at stores I don't normally use, the rule is always get in the line for the hot female cashier.
you are missing the point! the shops are entirely aware that single line is more efficient, its just that they dont want you to pass the cashier quickly. they want you to wait there. the trick is to keep the lines long enough so that people are bored in the line but not yet royally pissed off. near the cashiers is what is called the "the impulse zone" where small goods are placed, cigarets, newspapers, small choclates, condoms etc. by the time people go to the cashier they have already bought all they need but if you make them wait in the line they might buy some more out of boredom. in banks, airports, etc where they actually want the queue to pass quicly single lines are used - in shops they simply want you to stay longer in the store so you have lines at every cashier
The single line method is evil. It removes choice
from the customer. I want to avoid the cashiers
that insist on putting canned soup on top of
bread and eggs. (and get upset if you start bagging your own)
I avoid stores that use the single line method.
this is retarded. if we're all standing in different lines, how can they all be the slowest?
You are complaining about machines putting people out of work? Perhaps you need to return to the pre-industrial age. As for the bit about problems -- they have 1 person assigned to assist those who have problems with the machines, right now @ the rate of 1 person/4 auto-machines.
But I found, in my own experience, that problems come from people who don't know how to use the machines. I had problems the first few times I tried one, but being a computer person, I quickly figured out the interface. Once that happened -- no more problems.
I suppose you'd hate it worse if you just had to walk through a scanner that picked off all the RFID's of all the merchandise on you (as in the IBM commercial showing someone stuffing the lining of their long coat, full of merchandise, as if preparing to steal all of it). Then you swipe your payment card, slip (check's electronically scanned), or go to a cash line (also possibly automated w/talk of RFID's in money to prevent counterfeiting) and you're off.
Being scared of computers automating away jobs that used to be done by humans seems ridiculously out of place on a tech-site like "/.". You sure you are in the right place? Same goes for the lost Luddites who modded you to +4 insightful. Go find a flat-earth group to hang-out in -- you'd be more "at home", and think about evolving to the tech-age.
Normally, where the service time is very short, relative to the transaction time, the SQMS works very well (line up at a group of ATM terminals). In a situation where there are multiple servers to a tool-crypt facility, (One or two windows), the servers actually interfere with each other and therefore, each of the server's times is increased, However, the total wait time for an individual (queuing + service) is still the least. Walmart has a fast queue system (1-8 items), where they use single queue multiple cashiers. It works well for them because the path through the queue is filled on each side with candy, magazines, batteries for toys, etc. Cherry picking while waiting for service is very important aspect of adding sales dollars. In the multiple server, multiple queues, there is queue jumping, which takes place more often then you think, and since the time for service is long, you have time to read / purchase a magazine, consume a chocolate bar, or buy some crap before your turn at the cashier arrives. I also think that the MSMQ may require less floor space too due to arrangements to not manage a queue when volumes are customers are low. Thats my 2Cents worth.
Leslie Satenstein Montreal Quebec Canada
They have the one-line queue at TJ Maxx, and it couldn't work any better. I was in the line of last-minuters yesterday, TONS of people in one line and boomboomboom, we were getting ticked off every 30 seconds, if that.
You want to know how to help your kids? LEAVE THEM THE F*&K ALONE. --George Carlin
The title of this article is actually a bit misleading. It claims that "Scientifically, you are likely in the slowest line", however this is not what the video indicates. It only says that scientifically you are most likely NOT in the fastest line. Given three cashiers you are equally likely to be in the fastest and slowest line, but there is a 2/3 chance that you are NOT in the line the is fastest. Actually for any number of cashiers, you are equally likely to be in the fastest and slowest line, however you are only more likely NOT to be in the fastest line when there are at least 3 cashiers. If there are 2 cashiers, then there is a 50% chance of being in the fast one and a 50% chance of being in the slow one. Given 1 cashier you are always in both the fastest, and the slowest line. Given 0 cashiers, you are neither in the fastest nor the slowest line. I'm still considering the cases when there are fewer than 0 cashiers.
If there are more than a few queued at self-service, I look elsewhere. They are all amateur scanners, often confused by the unfamiliar [me included]
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