I’ve heard The Design of Everyday Things recommended a number of times and recently picked up a copy. This book was my introduction to design theory; the most in-depth information I had gotten on design up until this had come from blog posts. I don’t have much to compare the book to as a result but I found a lot of valuable information from it.
The book started out by laying the groundwork for the terminology used in the book. The clarification of “affordances” and “signifiers” was helpful given my lack of background knowledge. The two terms are often conflated as the same but the author noted that it is important to recognize their differences. Affordances are the abstract utilities provided by the product whereas signifiers are the aspects of the product that explain its abilities either directly or indirectly. The key to good design, Norman explains, is in creating useful and easily understood signifiers.
One other fundamental point that Norman reiterated throughout the book was that there is no such thing as “Human Error”. Many times we will blame faults on human error when the root cause was actually bad design. People tend to act in good faith and mistakes can be avoided or mitigated with well designed products.
Norman built on these ideas to provide actionable items for improving product design. He spent a lot of the book discussing mappings or the relationship between controls and their effects. The common example used for this was a stovetop and its burners. It would be clearest if the heat control for each burner could be physically attached to the burner it controls, but obviously this is impractical. The next best solution would be to mount the dial very physically close to the burner it controls, but that does not always fit with the overall layout of the stove. The next best, and most common, solution is to arrange the dials in the same shape as the burner arrangement. We can easily determine which dial controls which burner if they are in a clear shape.
One other means of ensuring that mistakes are not made is by enforcing constraints on the product’s abilities. The clearest example to me was the reminder to save a document when closing out a text editor. The program does not allow you to exit the program in one click because it can often result in a mistake of failing to save the work that was done.
I found the book to be pleasantly dense with information and there were a lot of good takeaways. This did make for a rather dry read at times, however, and I didn’t find the book to be as entertaining as I thought it would be. It’s a good middle ground between a textbook on design and a casual book or blog post.