The Pencil

An interface so easy even a toddler can use it.

I do a lot of drawing. By this I mean to say I make very large drawings that require hours and hours­, days and days, of focused energy with one particular instrument: the pencil. Spend that kind of time with a pencil and one starts to really pay attention to how it functions as a tool.

Mechanical pencil is a physical interface.

For starters, a pencil virtually disappears in the user’s hand. Rarely does someone fumble around trying to figure out how to work a pencil. It is very clear. It embodies all the technical hallmarks (affordances, constraints, natural mapping, feedback) in its simple design. It is a stick with a point on one end that makes marks. Once we know how to hold one (we learn this somewhere around age 2) we stop looking at it. We just automatically pick it up and use it.

A pencil, as a tool, exemplifies natural user interface. It provides the essential physical and tactile cues to allow a user to focus on the given task and not on operating the device. There is no interface noise, nothing to distract the user from the task at hand. And that is the point.

Gestural Interface

When we learn to write, we are not learning how to use a pencil. We are learning the gestures needed to form specific iconic shapes.  The focus is on the task of communication, which is complicated enough. The pencil is just the vehicle to record gestures, an extension of the hand. Any mark making device can be substituted for any other. We transition from the marking devices (pencils to crayons to pens to markers, to say, lipstick) easily because their design is similar; it is the gesture-making, not the tool, that requires attention and concentration.

Words are, then, a series of gestural motions that make specific marks and have specific meanings. Emotion does not come through just the words themselves. Users communicate anger, passion and urgency by pressing down. The interface of this device (the pencil), as an extension of the hand, gives the user an instinctive way to communicate emotion.

Physical Interface

Click inline button with thumb to advance the lead.

When technology met the pencil, the result was the mechanical pencil. With the mechanical pencil, the time consuming task of sharpening pencils disappeared. Instead, the user can lengthen the nib as needed without looking. With one quick gesture the sound of the click—mechanical, tactile, and auditory—lets users know it is working. Some mechanical pencils even have the pump button in line with the forefinger so users do not even have to move their hand to lengthen the nib. The opposite of complicated. Disruption: minimized.

Erase FEELS different than write.

When we have made an error while writing or drawing with the pencil, we simply flip the pencil over and erase. The error is gone. We reverse the motion, and it reverses the progress/process. The feel of the resistance of the eraser on the paper is so different from the tactile scratch and glide of the pencil that there is no mistaking which side is which.

Tactile Feedback

Tactile feedback and emotion.

The pencil provides the user clear and immediate feedback: the tactile and auditory feedback that tells us the mechanical pencil is reloading; the tactile feedback juxtaposed between the eraser and nib, the doing and undoing; and even how the surface of the paper feels through the graphite. Mechanical pencils, with their fixed points and spring mechanism designed to push the graphite forward, enhances that sensation. Even more satisfying is the tactile feedback when writing something impassioned – the pressure of the pencil to paper, and the tactile resistance that accompanies it, acts as a physical release valve for emotion that is simultaneously translated to the paper. Readers of the resulting dark, impassioned marks understand the emotion intuitively.

Whether physical or on screen, effective natural user interface is simply an interface that the user can operate it without having to stop to operate it. The pencil bears all the signs of a good interface. We, even as toddlers, can use it without thinking about using it.