The Design of Everyday Interfaces – 1

by krishnamoorthyb

Donald Norman is a legendary figure in the field of product design. His book The Design of Everyday Things first published in 1990 stands out as classic that has managed to retain its relevance in the face of the incredible changes we have seen in the past 20 years. I could never look at a door handle or knob the same way after I read his book. A new and updated version of the book was released in November 2013. Donald has also partnered with a couple of other folks to offer a ‘mini’ course on design at

Inspired by the book and by the course at Udacity, I am planning to document interfaces that I encounter regularly that either frustrate me or make me want to cry because of their sheer beauty (usability). This is part 1 of the a series. I am using some of the content I submitted as assignments for the coursework.

This post provides an example of a good signifier. A signifier is a visual or perceivable signal to the user of an object about an affordance of the object. Affordance is a word invented by Donald Norman. It represents a relationship between a property of an object and the capability of the user. For example, a regular chair provides the affordance of sitting to a person. It, however, does not present the same affordance to an elephant.  The following is an excellent example of a signifier in a Sennheiser Px-100 headphone.

Sennheiser headphone

The dots that you see are only on the left hand side of the headphone. The headphone distinguishes between the left and right side speakers and will fit snugly only when worn the correct way. Normal headphones would have a mark like “L” or “R” to indicate the side. These marks can be hard to read especially in low light conditions as they would be in the same color as the body of the headphone for better aesthetics. I love the fact that someone was thoughtful enough to provide a “physical” way to identify the left side of the headphone.