I've read quite a few technical and design books which discuss simplicity in passing, but it's rare to to come across one that focusses on it exclusively and authoritatively.

Giles Colborne's Simple and Usable: web, mobile, and interaction design (2010, New Riders) is one such.

In an interview, Colborne speaks for many of us I'm sure when he says:

I've been in a lot of meetings where people went in saying “we have to make this simpler” and have somehow come out with something more complicated and convoluted.

His book is an attempt to distil twenty years of interaction design experience into a handbook of practical strategies for actually achieving simplicity — not just paying lip-service to it.

Beautifully produced and richly illustrated, the print edition exemplifies Colborne's insistence that simplicity need not equate to blandness and I'm pleased I chose it over the cheaper eBook version.

More importantly, the book is full of concisely articulated insights, carefully chosen examples from the digital and physical worlds, and both general strategies and specific tips for simplifying web and mobile design.

I thoroughly recommend reading the book in its entirety, but here are a few of the ideas I found salient.

• The more complex a product/service is, the harder it is maintain and adapt to changes in the market.
• A vital question to ask (previously posed by Edward de Bono) is: Simple for whom? A new app that provides managers with a simple way of getting sales charts may mean sales reps now having to spend extra time doing complex data entry.
• The perception of simplicity is relative to the target user's expertise. For a product intended for general consumption, it's best to ignore expert users and focus on the vast "mainstream" majority and what they would consider "simple".
• A simple product/site/app is one you feel in control of. An example of over-simplification is the intimidating Japanese lift (elevator) with no buttons!
• Achieving simplicity requires persistence: things may start out simple, then become complex. Persevere until you reach Wendell Holmes' "simplicity on the other side of complexity".
• Try to resist features assumed to be essential to certain users. In fact the assumption may be wrong.
• Try to avoid lines in visual design, e.g. borders or dividers. They distract attention from the main focus by making people wonder sub-consciously about their purpose. Instead use tints or grid alignment to distinguish blocks.
• Simplicity is best achieved by understanding and designing around users' main goals rather than processes.
• Keep customisation options to a minimum: experts may like it, but for most people it is unlikely to be a core task.
• A key strategy is to displace complexity: for example a mobile app may only support a limited set of functionality, but the full range is available on the desktop version.
• Clever combinations can lead to simplicity, e.g. rear car window heating elements which double as the radio antenna.
• "Do one thing and do it well", may afford simplicity in isolation, however ten simple but separate tools replacing one complex instrument can just lead to clutter.