Thinking in Layers
One analogy I like to use for progressive enhancement are Peanut M&M’s (Figure 1.5). At the center of each Peanut M&M’s candy is, well, the peanut. The peanut itself is a rich source of protein and fat—a great food that everyone can enjoy (except those with an allergy, of course). In a similar sense, the content of your website should be able to be enjoyed without embellishment.
Figure 1.5 A confectionary continuum from peanut to Peanut M&M’s.
Slather that peanut with some chocolate and you create a mouthwatering treat that, like the peanut, also tastes great. So too, content beautifully organized and arranged using CSS is often easier to understand and certainly more fun to consume.
This is, of course, an oversimplification of progressive enhancement, but it gives you a general sense of how it works. Technologies applied as layers can create different experiences, each one equally valid (and tasty). And at the core of it all is the nut: great content.
Progressive enhancement asks you to begin with the core experience that is universally accessible and improve that experience when you can. Benjamin Hoh eloquently put it this way:20
- [Progressive enhancement] keeps the design open to possibilities of sexiness in opportune contexts, rather than starting with a ‘whole’ experience that must be compromised.
More often than not, experience begins with content. Clear, well-written, and well-organized content provides solid footing for any web project. It’s important to ensure that content is universally available too, which means it needs to be addressable via HTTP.21
To enhance the meaning of your content, to make it more expressive, you use markup. Every element has a purpose. Some elevate the importance of a word or phrase, others clarify the role a selection of content is playing in the interface, and still others aggregate collections of elements into related sections of a document. Markup gives more meaning to your content.
Visual design is a means of establishing hierarchy on a page. Contrast, repetition, proximity, and alignment help to guide users through your content quickly and easily. Visual design also helps you reinforce your brand and provide the most appropriate reading experience given the amount of screen real estate available to you.
You can use interaction as a means of reducing the friction of an interface. Hiding content until it is needed, providing real-time feedback based on user input, and enabling your users to accomplish more on a single page without constant page refreshes go a long way in humanizing an interface. They help your users be more productive and, when done well, can even make your creations delightful to use.
These levels, when stacked upon one another, create an experience that grows richer with every step, but they are by no means the only experiences that will be had by a user. In fact, they are simply identifiable milestones on the path from the most basic experience to the most exceptional one (Figure 1.6). A user’s actual experience may vary at one or more points along the path and that’s all right; as long as you keep progressive enhancement in mind, your customers will be well served.
Figure 1.6 Progressive enhancement visualized: the user experience gets better as opportunity allows.
A website built following the philosophy of progressive enhancement will be usable by anyone on any device, using any browser. A user on a text-based browser like Lynx won’t necessarily have the same experience as a user surfing with the latest version of Chrome, but the key is that the user will have a positive experience rather than no experience at all. The content of the website will be available, albeit with fewer bells and whistles.
In many ways, progressive enhancement is a Zen approach to web design: Control what you can up until the point at which you must relinquish control and let go.