Good usability is a feature you may not even notice

After weeks of 530am starts with my daugh­ter last year, and liv­ing where the local cafes don’t open ’til 800am, I couldn’t face another 3 hour stint before my first cof­fee, and so took myself off to the near­est pur­veyor of fine espresso mak­ers, and as luck would have it, picked up a Saeco machine for a great price. Not only did it pay for itself inside about 3 months, and make a great cof­fee, it had a design fea­ture I only dis­cov­ered by acci­dent recently.

While expen­sive machines are plumbed, machines like this one need to be topped up with water. You can imag­ine that try­ing to use the machine after it had run dry might be pretty bad on the inter­nals — a bit like run­ning out of coolant in your car’s radiator.

So a chal­lenge for the design­ers would have been to work out how to ensure users don’t let the water run dry. Of course, you could add elec­tron­ics to mea­sure water level and giver feed­back — say an orange light when water lev­els are too low, or even sim­ply shut off the device when there isn’t enough water — but you can see that these would add cost, more poten­tial for some­thing to break, or a big uptick in ser­vice costs — “it just stopped work­ing” phone calls would prob­a­bly increase dramatically.

As men­tioned, I only dis­cov­ered by acci­dent when I recently went to thor­oughly clean the machine the clever trick the design­ers used to get users to keep the water level suf­fi­cient. The water recep­ta­cle appears to be empty, even when it is 1/​3 full! The bot­tom third of the tank is recessed into the machine. So, when you look at the water level, it seems to be get­ting close to empty, even when it has over a third of its capac­ity left.

Robert Hoekmann spoke of for­giv­ing design in his keynotes at our recent con­fer­ences, where an appli­ca­tion is designed so that in effect you can’t make a mis­take. While you can still let this machine boil dry, with lit­tle fuss, or expense to the man­u­fac­turer the design­ers have made it much harder for users to do so. Beautiful design.

5 responses to “Good usability is a feature you may not even notice”:

  1. A good exam­ple of for­giv­ing prod­ucts. There are water cook­ers who use the same prin­ci­ple. The see through win­dow for water level starts a bit higher then the bot­tom, so the chance of burn­ing the cooker (with­out water) is smaller.

    But I am still not sure if this is good usabil­ity, you can still ruin your cof­fee maker. I mean, I like the point your are mak­ing and it is sure a nice usabil­ity touch, but it doesn’t fully pre­vent you from destroy­ing your cooker. If you are busy and doing mul­ti­ple things at the time I don’t think you will notice the water level.

    Good arti­cle, thanks.

  2. A good exam­ple of for­giv­ing prod­ucts. There are water cook­ers who use the same prin­ci­ple. The see through win­dow for water level starts a bit higher then the bot­tom, so the chance of burn­ing the cooker (with­out water) is smaller.

    But I am still not sure if this is good usabil­ity, you can still ruin your cof­fee maker. I mean, I like the point your are mak­ing and it is sure a nice usabil­ity touch, but it doesn’t fully pre­vent you from destroy­ing your cooker. If you are busy and doing mul­ti­ple things at the time I don’t think you will notice the water level.

    • By:john
    • June 2nd, 2008

    Hi Niels,

    while you can indeed even­tu­ally boil the machine dry, because of the way it works, it’s much less likely.

    It only uses water while you are mak­ing a sin­gle cup of cof­fee, or steam­ing milk — so you are actively using the machine while water is being used. You’d prob­a­bly have to make 10 cof­fees or more with no vis­i­ble water in the machine before it boils dry.

    Im actu­ally not sure what hap­pens if it does go dry — to pre­cious a device to find out!

    john

  3. Hi John, thanks for your quick reply, I agree with you

    The machines look nice and make great cof­fee, I tried it once.
    It is really good you can still make 10 cof­fees when you don’t see the water level so chances are pretty slim your machine will run out of water.

    But the price, quite expen­sive, also in use. I write a lot about these kind of usabil­ity prob­lems with prod­ucts, feel free to check it out. I am going to fol­low this blog closely!

    • By:john
    • June 2nd, 2008

    Hi Niels,

    you can buy espresso mak­ers, at least in Australia, from about $50 and up. The real­ity is, until you start pay­ing say $200 or more, they prob­a­bly won’t last long, nor make a very good coffee.

    The good thing about cof­fee mak­ers is, if you drink cof­fee reg­u­larly, they pay for them­selves quite quickly. For exam­ple, where I live, its $4 for a large cof­fee — so I save about $3 a day after cof­fee and other costs by mak­ing my own. So, you can pay off even a quite expen­sive machine in 4 – 6 months (much quicker if more than one per­son in the house­hold drinks cof­fee).
    After that, it effec­tively pays you to make coffee!

    Now, that’s nice design.

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