Home-made instant poka-yokes

Everyday poka-yoke

Update: Also known as Useful Landmines in the 43 Folders world - thanks Pantufla!

Mistake-proofing - poka-yoke - can be as simple as encouraging/forcing yourself to do things in a sequence, to avoid forgetting or avoiding intermediate steps. If you’re the sort of person who hangs a jacket or bag on the door handle, so it can’t be forgotten on the way out, puts things in front of the door so you can’t forget them when you’re going out, or at the top or bottom of the stairs so you’ll remember to carry them to their intended destination next time you’re using the stairs, you’re engaged in mistake-proofing. You’re introducing a behaviour-shaping constraint to assist your own effectiveness.

In the above photo, putting the mobile phone (on-charge) inside a shoe makes it more likely that it will be remembered when going out: the act of putting the shoes on requires the user to pick up the phone, which could otherwise be easily forgotten. Similarly, Mark Hurst (of Good Experience and ‘Broken’ fame) regularly features two very simple poka-yoke procedures in his Uncle Mark’s Gift Guide & Almanac:

How to remember if the batteries aren’t in your camera

Summary: If the batteries are dead, or aren’t in the camera, keep the battery compartment open.

Description: When you’re charging your camera batteries (in a wall charger, say), keep the camera’s battery compartment open. That way, if you pick up your camera to put it in your pocket or purse, you’ll see that the battery compartment is open and will remember that the batteries aren’t in it.

Leaving the camera battery door open

There’s also this:

How to make sure they see the papers you dropped off

Summary: Put the papers on their chair.

Description: Here’s a tip I learned years ago and have used ever since. If you want to make sure that someone sees the papers you dropped off at their desk, put the papers on their chair. The natural inclination is to drop the files on the keyboard, or beside the mousepad. What’s the first thing the person does when they get back to their desk? They shove the papers aside, onto a nearby pile. They want to check their e-mail immediately, and those papers are in the way!

But put the papers on their chair, and watch what happens: the person refuses to sit on them! They take a second to pick them up, and while they’re in-hand, the person takes a look at the files while they get comfortable in the chair. Bingo: you guarantee attention to your drop-off.

Papers on chair

Of course the papers-on-chair method can also be used to remind (or discipline) yourself about dealing with important papers.

This kind of very simple sequencing poka-yoke comes almost naturally in our everyday lives, at least with certain tasks. Sometimes it’s simply reminding ourselves to do something (e.g. putting a Post-It note somewhere we can see it); other times it’s trying to prevent us proceeding until some action has been taken (e.g. putting a Post-It note right in the middle of the computer screen so we can’t ignore it). Donald Norman’s Things That Make Us Smart has some interesting discussion of the power of Post-It notes and their importance as “information in the world”, disburdening some of our mental load - also part of the whole Getting Things Done phenomenon.

Sometimes we even (consciously or otherwise) try to ‘trick’ ourselves into behaving how we want to (or know we should) - the random offset alarm clock (patent; Halfbakery discussion) and Gauri Nanda’s “runaway success” Clocky being examples that spring to mind. (I once had a bedside clock radio where the button to set the minutes no longer worked, which meant that I could only set it either on-the-hour, or, because I forgot to do it at the right moment, set it maybe between 5 and 30 minutes fast. That meant that there was an uncertainty built into every time I glanced at the display, and indeed every time the alarm went off. I was rarely late, as a result.)

I have a hunch that almost trivially simple sequencing poka-yokes (in particular) could be important in designing for sustainable behaviour, such as reducing energy use and waste generation. For example, if your rubbish bin had a recycling box built into the top, so that you had to lift it out of the way (hinged, perhaps, to make it hassle to remove entirely) before putting anything into the main bin, it would be difficult to ignore the recycling box. Hence, learning as much as possible about different methods people use to mistake-proof themselves, or shape their own everyday behaviour, is likely to be useful in exapnding this line of research.

So, what are the everyday home-spun (or otherwise) tricks you use to help mistake-proof yourself?

I believe in mirror-queues

Meagan Call has written a very interesting piece examining the technique used in some (women’s) public restrooms* of moving the mirrors to the wall near the entrance/exit, rather than behind the sinks as might be expected (and is usually found in mens’ facilities), to lessen queueing and speed up throughflow:

No mirrors behind the sinks: photo by Meagan CallMirrors by exit instead: photo by Meagan Call

Women often linger, using the excess water from their recently scrubbed hands to squish, flatten, and fluff their hair. I’ve seen women who don’t bother to wash their hands bend over the sinks to play with their hair or re-touch makeup. And of course, some women go into the restroom for the sole purpose of looking into the mirror. No mirror equals less congestion, people washing their hands can get to the sinks more easily, and will leave more quickly.

Moving the mirror near the doors is actually an intelligent solution… by moving the mirrors away from the water, primping is less desirable. In addition, by placing it in the pathway of the door, people are more likely to feel foolish and in the way, and are therefore more likely to pass by quickly. The open space does not invite people to stay and look in the mirror.

Meagan’s analysis is spot-on - this is a clever technique which is subtle enough not to be noticed by the majority of users, but which nevertheless shapes their behaviour. The agenda is one of social benefit (for the greater good of the other users, reducing congestion) rather than explicitly commercial (in the context of the service area where the facilities are located), but it presumably has the effect of reducing complaints, hence increasing customer satisfaction even if only marginally.

We’ve looked before at some of the issues around mirrors in a retail environment, but in a confirmation/corollary of Meagan’s thoughts, I’ll end with two pertinent quotes:

Stand and watch what happens at any reflective surface - we preen like chimps, men and women alike… Mirrors slow shoppers in their tracks, a very good idea for whatever merchandise happens to be in the vicinity.

Paco Underhill, Why We Buy.

A large hotel in an American city received many complaints about the slowness of its elevators. It installed mirrors next to the elevator doors. The complaints ended.

Lawrence Lessig, Code and Other Laws of Cyberspace

………..

*/bathrooms/toilets/conveniences/other

Photos from Meagan Call.

Destroy everything you touch

The sandpaper cover of Debord's Memoires. Images from eBay

We can’t help but be familiar with the concept of ‘malicious code’ in the context of computer security and programming, but in general the idea of products or technology which, as they’re used, sabotage or degrade the performance of a ‘rival’, is intriguing and not well-explored. Scott Craver’s Underhanded C contest is a fascinating example from the ‘white hat’ side of the fence; Microsoft’s use of deliberately targeted style sheets on MSN.com to degrade Opera’s performance is another; and the CIA’s alleged planting of software bugs in Russian pipeline control software is a third. The Sony DRM rootkit might also fall into this category (as would this!)

But on a much more concrete level, we have this playful example: Memoires by Guy Debord, psychogeographer and Situationist, was originally published with a rough sandpaper cover:

Memoires was written, or rather assembled, by Guy Debord and Asger Jorn in 1957. Debord himself often referred to Memoires as an anti-book, and the original edition was bound in sandpaper, that it might destroy other books. The text is entirely composed of fragments taken from other texts: photographs, advertisements, comic strips, poetry, novels, philosophy, pornography, architectural diagrams, newspapers, military histories, wood block engravings, travel books, etc. Each page presents a collage of such materials connected or effaced by Jorn’s structures portantes, lines or amorphous painted shapes that mediate the relationships between the fragments.

(from an article by David Banash)

Debord's Memoires. Images from eBay

And from this article by Christian Nolle:

The book is most famous for its sandpaper cover. An auto-destruction feature that enabled it to damage not only the book it might be standing next to in the bookshelf, but also the person who would be reading it. An anti-book to destroy all other books.

Permild writes: “Long had he [Jorn] asked me, if I couldn’t find a unconventional material for the book cover. Preferably some sticky asphalt or perhaps glass wool. Kiddingly, he wanted, that by looking at people, you should be able to tell whether or not they had had the book in their hands. He acquiesced by my [Permild’s] final suggestion: sandpaper (flint) nr. 2: ‘Fine. Can you imagine the result when the book lies on a blank polished mahogany table, or when it’s inserted or taken out of the bookshelf. It plans shavings of the neighbours desert goat [?]’.

In all the literature that I have located, Debord is the person who is refered to as the inventor of the sandpaper cover. However, as it turns out Debord had nothing to do with it… Permild continues, «Asger loved - as he often expressed it, to place small time controlled bombs». This was certainly a bomb. A bomb invented by the printer, whose job is normally of a technical nature. The sandpaper cover was a really good idea, but practically it never managed to practice what it preached. It did, however, make its readers conscious about handling it or where to place it.

One the other hand, Memoires placed itself on a shelf among precious object, something to be handled with great care… The American Hakem Bey did something similar in the 1970s. In homage to Guy Debord, Bey made a book with sandpaper on the inside. This way he rendered the book into auto-destruct mode if you would ever dare to read it. A potential bomb to go off if you would open it. Memoires, on other hand is a bomb, not a potential bomb. No matter how you would handle it, there was always the danger that it could damage your precious collection of 1920s French poetry.

The photos above come from this French eBay listing - the copy on sale reached €3,810.

Full, tilt

Balancing bowls. Image from Royal VKB websiteJan Hoekstra’s Balancing Bowls for Royal VKB (via Boing Boing) are an interesting ‘portion control/guidance’ solution - as Cory Doctorow puts it:

The tilt is tiny, all of 3 degrees, and the net effect is very satisfying — you gradually add snacks to the “light” side until it makes a soft and very definite *click* as it falls.

This kind of ‘very mild persuasion’ example is a great demonstration of how a simple physical property can be used to inform the user - the conventional modern solution in this area might be to monitor users’ behaviour, e.g. by weighing the amount of food put into the bowl, and then display it electronically, with an indication of whether a pre-set portion size has been exceeded. But these bowls simply tilt, with no electronics or moving parts (other than the bowl itself) necessary. It’s an elegant poka-yoke style solution.

Portion perception (and unit bias) is a fascinating area - we’ve looked briefly at it a few times - but I hope to explore it in more detail in due course, along with a review of Dr Brian Wansink’s Mindless Eating - in a post about how cognitive biases could be used in designing behavioural change.

Do you really need to print that?

Do you really need to print that?
Do you really need to print that?

This is not difficult to do, once you know how. Of course, it’s not terribly useful, since a) most people don’t read the display on a printer unless an error occurs, or b) you’re only likely to see it once you’ve already sent something to print.

Is this kind of very, very weak persuasion - actually worthwhile? From a user’s point of view, it’s less intrusive than, say, a dialogue box that asks “Are you sure you want to print that? Think of the environment” every time you try to print something (which would become deeply irritating for many users), but when applied thoughtfully, as (in a different area of paper consumption) in Pete Kazanjy’s These Come From Trees initiative, or even in various e-mail footers* (below), there may actually be some worthwhile influence on user behaviour. It’s not ‘micropersuasion’ in Steve Rubel’s sense, exactly, but there is some commonality.

Please consider the environment

I’m thinking that addressing the choices users make when they decide to print (or not print) a document or email could be an interesting specific example to investigate as part of my research, once I get to the stage of user trials. How effective are the different strategies in actually reducing paper/energy/toner/fuser/ink consumption and waste generation? Would better use of ‘Printer-friendly’ style sheets for webpages save a lot of unnecessary reprints due to cut-off words and broken layouts? Should, say, two pages per sheet become the default when a dicument goes above a certain number of pages? Should users be warned if widows (not so much orphans) are going to increase the number of sheets needed, or should the leading be automatically adjusted (by default) to prevent this? What happens if we make it easier to avoid printing banner ads and other junk? What happens if we make the paper tray smaller so the user is reminded of just how much paper he/she is getting through? What happens if we include a display showing the cost (financially) of the toner/ink, paper and electricity so far each day, or for each user? What happens if we ration paper for each user and allow him or her to ‘trade’ with other users? What happens if we give users a ‘reward’ for reaching targets of reducing printer usage, month-on-month? And so on. (The HP MOPy Fish - cited in B J Fogg’s Persuasive Technology - is an example of the opposite intention: a system designed to encourage users to print more, by rewarding them.)

Printing is an interesting area, since it allows the possibility of testing out both software and hardware tactics for causing behaviour change, which I’m keen to do.