2008/05/26

Unfriendly traffic signs

In Europe, like in North America, and like in many other regions in the world, everything seems to be have been built around the concept of car transportation: from the location of the buildings and how they are designed, to the daily social organization of everyone. This has an unexpected but important consequence which is directly in relation with user interfaces.

As a driver, passenger, cyclist or simple pedestrian; in a large city, or in the countryside; we are literally surrounded by traffic signs. Everywhere. From the largest highway, to the most modest track suitable for vehicles. It might be surprising, but traffic signs are actually user interfaces. They represent an interface between the travelers and local authorities, by communicating about potential risks, limitations, and other pieces of information. But like any other kind of user interfaces, traffic signs need to be well designed.

In the driving school, I learnt a simple rule which helps understanding most of the traffic signs found in several countries of Western Europe. Consider the shape and the dominant colors of any sign.


  • A white disc surrounded by a red border forbids.



  • A white triangle surrounded by a red border warns about a danger.



  • A blue square informs.


  • A blue disc constrains.


Great, isn't it? It seems so easy. Most probably, a similar set of rules exists in your own region. Next time you travel in car with children, you can propose to them a funny game. Explain the rules above, then let them imagine what is the true meaning of each traffic sign they will see. Thanks to the shape, the color and the symbols inside the sign (most of them are relatively pertinent); and with some little help, they should quickly find intuitively the correct answer.

Unfortunately (and this is actually the real point of my post), you will also very quickly meet some signs which do not fit into any of the categories described previously. It's not a disc, nor a square; unexpected color, obscure symbol. No chance to "guess" the real semantic, if you don't know it already.




Worse, those four signs represent about 10% of all the signs installed all along the roads. My question is the following. Why having created a very nice set of rules which apply only to 90% of the traffic signs, and let all the remaining elements with a complete customized and chaotic style? Does it make really any sense? In fact, I have no answer concerning that specific example; but there is a moral to this story. It is applicable to software engineering, but probably to any other engineering discipline as well.

As a designer, you have to establish rules and principles which will describe the general working and the usage of your system. But you have also to apply those rules from start to finish. Do not suffer any exception. It is commonly accepted that exception proves the rule. But I think it's only an easy excuse to not refactor your work when it needs to (Agile followers will appreciate the generalization of the concept). If things do finally not match well to the rules, it is usually a smell of poor preliminary specifications. Change the things or rewrite the rules, but make easier the life of your future users. As a designer, if you don't follow your own rules, who else?

2008/05/20

Easy symbols

Symbols are very important in user interfaces. Due to space constraints, the designer often needs to represent concepts with symbols. They usually act as visual or auditive shortcuts (I have a funny anecdote about an exclusively auditive interface, that I will soon talk about in a future post.)

Recently, I had to work on the conception and the development of a large software project with a very significant user interface containg a lot of forms and panels. In order to improve the usability of the system, I decided that I would need a nice but simple icon library to decorate the interface.

Being not a graphic designer, I have found a simple way to quickly create such an icon library.

1. Get a basic and sober icon frame. You can find plenty of them for free on Internet.



2. Open the frame image in your favorite image processor.

3. Add a new layer above the frame, then write a character with any symbolic font such as Webdings or Wingdings.



4. Add a shadow or some other effect. Et voilĂ  ! In less than 10 minutes, you get a nice set of icons you can extend and vary ad infinitum.

2008/05/16

The elevator front panel

I live with my lovely wife Jacinta in a nice duplex located at the third floor of an apartment block. We have bought it some years ago. The building has 4 floors. But surprisingly, when entering the elevator, you are faced with the following panel :

One could say it is just funny. But my opinion is that having a complete 10-digits pad and a 3-digits display, to only just move between floor 0 and 3, is plain stupid. Realize that 70% of the panel is completely useless !
If you look carefully, you can even see a dot key! Frankly, I have no idea what usage such a key may have in an elevator. Perhaps someone could desire to go to the floor 2.5 ? Earlier today, I made several trials. And fortunately, the elevator had silently rejected my request to visit hell when I typed -666.
More seriously, the reason why the architect took the decision to install such a panel, is far beyond my understanding. But there is a lesson to remember.

When designing a system, you do not have always the possibility to create yourself a dedicated user interface. Sometimes, you have no other choice but to apply an existing template. Should this happen, do not follow the famous proverb which says "He who can do more can do less". In term of user interface, this will lead you inevitably to a failure. As Patrick Smacchia explained recently in his excellent blog about NDepend, let "make the simple things simple (...)". Interface designers should always remember that very sentence.

2008/05/15

A few preliminary words

As the title of this blog might suggest, the main topic of my future posts will be user interfaces. But despite the fact that I work as a corporate software engineer in a large automotive company, I do not intend to restrict myself to software interfaces. In fact, I would like to speak with you about all the kind of human/machine interfaces, which we, as human beings living in a modern society, have to deal with daily... more or less successfully.

I am going to expose my thoughts about what make interfaces good or bad. I will relate anecdotes inspired from my professional experience, but also from my private life concerning all those funny, stupid, or amazing interfaces which allow (or sometimes prevent) us to interact with the rest of the world. We will also try to have a look at what and who is hidden behind interfaces.

I hope you will enjoy that blog as much as I will enjoy writing it.

See you soon...