312 votes

What's wrong with USB sticks that you need 3 tries to plug them in correctly?

In my experience a USB plug needs a bit of pressure to go in the port. It’s enough pressure to make me wary that I might break it if I’m putting it in the wrong way. After reversing the plug, it ...
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  • 3,323
172 votes

Do signs printed on the road offer a significant advantage for the user over signs on a post?

Here in Finland the main reason is this: Image source Road markings are used to denote speed limits but never as a primary mean. And as Jung Lee points out, re-applying road paint is labor intensive,...
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167 votes
Accepted

Why do idle elevators close the doors?

A Google search doesn't really provide me any answers but I do have some ideas on why the doors would close: 1: Time Efficiency (As stated by Andrew, Ruudt, and Angelo) Closing the door reduces the ...
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  • 3,663
164 votes

What's wrong with USB sticks that you need 3 tries to plug them in correctly?

Short answer: Design commonly causes misalignment Most plugs or ports have a flared edge, beveled plug or some other design that allows for the orientation of the plug to be slightly off and still ...
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156 votes

What's wrong with USB sticks that you need 3 tries to plug them in correctly?

Physical symmetry without symmetry of use I'm surprised that so many of these answers are addressing the consequences of poor design without discussing what made it a poor design in the first place. ...
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  • 1,695
145 votes
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Why are aluminium soda cans typically round instead of square?

It is a combination of manufacturing and usability... but mostly manufacturing. Doing a quick web search for "why are soda cans round" (Google does a decent job) yields multiple insights in the issue....
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138 votes
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What's the purpose of "This page is intentionally left blank" we see in books?

This wikipedia page sums it up quite nicely https://en.wikipedia.org/wiki/Intentionally_blank_page Such pages may serve purposes ranging from place-holding to space-filling and content separation. ...
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  • 15.1k
134 votes
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Why is sugar not in a shaker?

Because, at the table, a shaker is entirely the wrong dispenser for sugar. Shakers are used to sprinkle small amounts of a substance over an area, which is exactly what you want for salt and pepper. ...
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131 votes

What is the benefit of 2 drive thru lanes at a fast food restaurant?

I am in the fast food business having owned five units for over 30 years but don't have a unit with two lanes. The reason for two lanes is a matter of timing from McDonald's research into this that ...
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  • 2,813
130 votes

Why do idle elevators close the doors?

Closing the door for the floor the elevator is on reduces the time, the elevator can serve another floor upon request. The time is saved due to omitting the door closing step. Considering that ...
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119 votes

I'm designing a no-data USB cable : How should the end be marked?

Unfortunately such cable is not compliant with USB specification, as even in usb power delivery the data lines are used to negotiate power. You should not mark it with USB (or even USB-like) logo at ...
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  • 1,195
108 votes
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Why do showers have "hot" and "cold" knobs rather than "temperature" and "quantity" knobs?

You are totally right As with many other devices (eg the QWERTY keyboard) the hot/cold tap persists not because it's the most usable design, but because of: Cost since proper temperature control ...
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  • 40.4k
103 votes

Toilet flush buttons

I think icons are the best possible way to convey the information about different flushing amounts. I see too much uncertainty by relying only on button relative sizes and ease of use. It can be a ...
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94 votes
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Why do traffic lights have three separate light bulbs instead of having one?

Historically It is a simple fact that traffic signals were introduced in 1868. From The Origin of the Green, Yellow and Red Color Scheme for Traffic Lights: In London, England in 1865 there was a ...
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90 votes
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How to convey: "don't move until the task is done!"

Great question! This is an good case for microinteraction design. Microinteraction objectives In descending order of priority: Provide clear affordance for user to place card/wallet on reader ...
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  • 40.4k
80 votes
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How to avoid the "local elevator" problem?

Replace the panel A with buttons “to rooftop” and “to garage” instead of “up” and “down”. Now elevator 1 is reserved for special floors and most people use elevators 2-4.
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  • 3,323
79 votes

What's wrong with USB sticks that you need 3 tries to plug them in correctly?

The underlying problem, as I think we all know, is that the tactile feedback you get with an incorrectly oriented plug is hard to distinguish from the tactile feedback with a slightly misaligned plug. ...
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  • 894
76 votes

I'm designing a no-data USB cable : How should the end be marked?

You can never beat straight text ("Power Only"); that way, there can be no confusion. That said, I actually have such a cable at home which has an icon very similar to this in a raised profile on ...
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69 votes

Why is sugar not in a shaker?

Salt and pepper are (generally) used in smaller amounts. A sugar packet also is a sort of measuring unit; it's roughly as much as a sugar cube. That means that you can use it for coffee and tea ...
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  • 8,271
68 votes

How to avoid the "local elevator" problem?

On further thought, another solution could be to implement a singular, digital wall panel where users can indicate to which specific floor they are intending to go, much like the ones found in many ...
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  • 1,061
63 votes

Toilet flush buttons

OK, how about this? Should be understandable by everyone, irrespective of culture.
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59 votes
Accepted

Why put a warning sticker over the warning on this product?

Is there any chance the label pictogram is actually 10x10mm? Guidance on Labelling and Packaging Version 2.0 - September 2016 states in section 5.2 (Size of the label and of the label elements) that ...
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57 votes
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"Do Not Disturb" tags in hotels, how can they be improved?

Various hotels I have come across (though I remember that primarily from China) had simple lamps with the respective do not disturb and please clean room signs next to the door and accordingly labeled ...
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  • 1,648
56 votes
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Why do we prefer shiny finish on cars and dull finish on devices?

Practical origins defined our tastes When car finishes became shiny (because they weren't always) [1,2] due to the availability of the required technology and paint materials, it was mostly for ...
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  • 11.5k
55 votes
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Toilet flush buttons

Because litres are a unit used everywhere across the world, a non-language dependent text solution is to label the amount of water used. Typically the symbol "L" is recognised as litres in almost any ...
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  • 1,100
54 votes

"Do Not Disturb" tags in hotels, how can they be improved?

I have seen indicators that are inserted into the key card slot so that keys can't be inserted until the indicator is removed. These solve the problem of being accidentally changed, since they are ...
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  • 1,986
51 votes
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Color choice for maximum legibility of text on glass

There is a better solution, at least in terms of legibility, perhaps not so much aesthetically. And I'm 99% sure you've already seen it. Black border, white letters. White letters are almost always ...
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  • 8,271
49 votes

Why do traffic lights have three separate light bulbs instead of having one?

One reason for the three lights, in the UK at least, is that you have many states. Two of the lights can be on at one time, i.e. red and amber signalling that you should get ready to go, where as a ...
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49 votes
Accepted

Why are messages on the road printed in reverse?

You read as you approach. Theoretically. In reality, levels of visual acuity mean that some people (like you and I) can read the whole block at once. Another reason that painting information on the ...
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  • 21.1k
49 votes

What is the benefit of 2 drive thru lanes at a fast food restaurant?

It's better for some situations like a quicker user gets through the line faster. Example: a car full of kids takes 3 minutes to order. A single person who knows what they want takes 30 seconds to ...
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  • 501

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