Is it just me or is this door stupid?

Have you ever tried to open an exit door like the one in the picture and pushed the wrong side of the handle? Bad news is it feels very stupid when you can't open a simple door from the first attempt. Good news is you are not alone!

http://i01.i.aliimg.com/photo/v0/106222079/FIRE_EXIT_DOOR.jpg

Until a very recent point of time, cognitive psychology had promoted the idea that humans are reactive creatures who behaved according to a stimulus-response mechanism. For example, when you see a 'Press any key to continue' message, your react (or respond) to the message by actually pressing any key. It's an immediate reaction to a sudden stimulus. This notion has significantly influenced the design of things around us, computer devices and software included. To illustrate this in more depth, let's go one decade back in time. Remember the good old Nokia 3310?

Nokia 3310 - http://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Nokia_3310_blue.jpg/150px-Nokia_3310_blue.jpg

Here is how you would send an SMS using Nokia 3310 (and most of other old devices):

1) You go to Messages - as a response to seeing the Messages icon on the screen.
2) You write the message - as a response to seeing the large text box and a blinking cursor.
3) Once you're done, you go to 'Options' - as a response to seeing the 'Options' button.
4) Then you hit Send - as a response to seeing the send option.
5) Finally, you key in the number of the intended recipient for the message - as a response to seeing the small rectangular box that says 'number'. (or you choose a recipient from your phone book).

You can see that every step in the process is based on the assumption that if a stimulus is strong enough to trigger some behavior, then the user will respond in the correct way.

For certain things, the stimulus-response mechanism has been employed very effectively - until today. For instance, red and green colors have been consistently used to signal unsafe and safe operations respectively. Almost every new phone uses the green color to 'Answer' a call and the red to 'Reject/Decline' a call.

HTC - http://htcevo3dtips.com/wp-content/uploads/2011/09/HTC-EVO-3D-answer-call.jpg

iPhone - http://www.filecluster.com/reviews/wp-content/uploads/2008/11/iphone_fake_calls.jpg

Nokia - http://dailymobile.se/wp-content/uploads/2011/06/incoming_call21.jpg

Nonetheless, the assumption that everything could be designed based on stimulus-response turned out to be overambitious. It is unreasonable to expect all humans to respond to a given stimulus in the same exact way. The burden is on the developer or/and the designer to ensure that the stimulus is strong enough so that most users may respond in the intended way. And unless the stimuli were somewhat universal (such as red and green), that was simply too much to ask. So what is the solution?

Well.. It turns out that humans are not only reactive after all. They are also intelligent proactive beings. Cognitive psychology turned upside down when we came to the realization that humans do not simply react to stimuli, but rather build expectations, anticipate events, and most importantly create mental models. And that is precisely why humans complain about things when they do not align well with their mental models. For example, before you open a water tap, you build a mental model of the path of the water. Once the water starts running, it should pour right into the sink. When it doesn't, you realize that something is off.

http://pic.epicfail.com/wp-content/uploads/2009/07/sink-fail.jpg

Now that is a very simple example, but it highlights a very important principle in the psychology of engineering. Once we absorb the concept of mental models, we will be able to understand why in the old days some people called call centers to ask where to find the 'any' button on their keyboard. We will understand why when many people see a big door handle, they do not know where to push. In their mental model, a door has to rotate around an axis on either side of the door. And unless this side is clearly marked (like in the picture below), it is difficult to know where you should apply the force to push. Needless to say, if you have to write instructions for opening a door, then maybe your design is simply stupid.

Don Norman & The Design of Everyday Things

At this point, you should also be able to explain why new phones handle sending messages the way they do. Using an iPhone or virtually any new mobile device (including Nokia devices), you will notice that the process of sending a message is pretty much the same except for one major thing. Can you guess what has changed? 

The key difference is that with newer models steps 2 and 5 are swapped. You no longer type the message and then choose the recipient. You do it the other way around. Because, according to our mental model of communication, we almost always think about the recipient before we think about the exact content of the message. "I want to text Sam to see how he is doing," "I want to tell Sara that the meeting is cancelled," "I will tell everyone about the party"...etc.

In the next post of the usability series, we will expand on this concept a little bit more and look at its practical applications in building user interfaces.