Design limitations and trade-offs
The key design factor driving recent ebook growth is readability on small screens, and the best way to achieve this today is to keep things very simple. Any deviation from this will limit your potential readership.
The problem is multiplied if you’re planning to add rich media such as video, audio, animation and interactive features.
Design features are improving with advances in formats, ebook creation tools and more powerful e-reader devices — but you should use them with care.
For now, there’s an inescapable rule: Each new feature or design innovation you add will lower potential readership.
By all means experiment a little and push some boundaries, but understand the impact and introduce enhanced features carefully, as we’ll discuss below.
Usability: What publishers can learn from web developers
An ebook is a piece of software as well as a book. Usability will become an increasingly important design consideration as ebooks become more sophisticated and interactive.
Usability research and testing studies the way people interact with software, whether in the form of programs on your computer or websites.
What is usability?
According to usability expert Jakob Nielsen, usability is about ease of use but most importantly it’s about the quality of the experience. He defines five quality attributes of usability:
- Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
- Efficiency: Once users have learned the design, how quickly can they perform tasks?
- Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
- Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
- Satisfaction: How pleasant is it to use the design?
Source: Jakob Nielsen, Usability 101, http://www.useit.com/alertbox/20030825.html
Most of Nielsen’s work concerns the web but we can see that ebooks and the web share an increasing amount in common. For a narrative work which progresses in linear fashion from the first page to the last, there’s not much the publication designer can do to change usability. But as you move to enhanced ebooks, usability issues will move to the fore.
This usability study examines non-fiction ebooks and gives some insight into the usability issues that designers should consider. http://www.nngroup.com/articles/nonfiction-ebooks/
Designing for variations in screen size and type
One of the biggest challenges is designing for screen variations: big, small; portrait, landscape; high resolution, low resolution; color, mono.
Dealing with this just got a lot easier, thanks to a feature in new ebook formats (and in modern web browsers). The feature is called media queries.
Media queries let designers add several style sheets to an ebook, each one optimized for a particular screen type. They automatically detect the screen type and deliver the style sheet to match it.
Considerations for ebook design
If you want your ebook to use features that go beyond the simple, universal feature set of EPUB and basic Kindle formats, you should consider:
- Will gains from enhanced design justify the loss of potential readers?
- Can I achieve enough of my design goals with simpler, more widely-accessible formats?
- What share of the market will be able to read the enhanced ebook?
- Are my target readers early technology adopters, hence more likely than the average to be able to read it?
- Will most sales happen early or will the ebook have a long life, allowing the pool of e-readers to catch up?
- Can I use fallbacks to retain compatibility with older e-readers
In some cases, it might make sense to push forward early, especially if you’re writing for a group who are likely to be early adopters of new technology, or if your book simply wouldn’t make sense without the advanced features. But go in with your eyes open and carefully screen the use of any such features before you adopt them.
Fallbacks: A way to use new features without losing older e-readers
A fallback is a way to ‘have your cake and eat it too’. If a new feature is not supported by older e-readers, your ebook can be programmed to use an alternative that is supported – a fallback.
Both EPUB3 and Kindle KF8 support fallbacks that will help to smooth the introduction of new features.
Fallbacks won’t serve as complete replacements but they’ll help ensure the new ebook doesn’t ‘break’ on older e-readers and will allow you to design a better user experience.
Nor will fallbacks solve all compatibility issues, and the more advanced the new feature is, the more complicated a fallback becomes. For example, if you’re planning an ebook with extensive use of multi-column text, SVG images, video and interactive quizzes, you’ll have a lot of work to produce effective fallbacks and might find that you’re better off with two editions, or waiting.
Amazon is using fallbacks to juggle its introduction of the KF8 format. Older Kindles aren’t upgradable to KF8 so Amazon is reducing the potential problems this could cause (and speeding up migration to its new format) by building fallbacks into its Kindle ebooks. Unlike the EPUB market, Amazon doesn’t have to rely on publishers alone to do this.
How long does it take for new ebook features to reach readers
The ebook industry, young as it is, is at the start of another major technology shift — the move to enhanced formats — which publishers will have to navigate carefully.
Technology improves at a much faster rate than people’s adoption of it because of the inertia or ‘drag’ that comes from the installed base of hardware and users. It can take years for new technology features to be widely adopted if they rely on existing users to upgrade or replace their systems. And the more people there are using a technology, the longer it takes for changes to filter through.
We’re yet to see how long it will take for older e-readers to work their way out of the system but it will certainly be years, not months. Change happens more quickly if:
- There is a small installed base of users. In most countries (unlike the US), e-reader use is still small so new features can get established fairly quickly.
- A manufacturer controls the whole ‘ecosystem’, as Amazon and Apple do. Upgrading is easier (and often automated), consumers can be offered incentives to replace old equipment, and new features can be rolled out in a more orderly way.
- Updates can be done via software updates rather than hardware. A lot of e-reader hardware and all e-reading apps can be updated to support new formats via software updates. Another important factor: Whether software is updated automatically or has to be manually updated by the user.
- New units are cheap or heavily subsidized, encouraging rapid replacement of old hardware
This list shows that Amazon’s control of the entire Kindle ‘ecosystem’, and the fact that all of its devices are internet-connected for automatic updates, gives it a big advantage when introducing new features. So its new KF8 format might get established more quickly than EPUB3 which requires lots of independent manufacturers to cooperate and coordinate.
But Amazon also has challenges: It is vulnerable to competitors like Apple because it has a large installed base of older Kindles which must be replaced while Apple can introduce most of its innovations through automatic software updates.
Find out more about this topic on our Digital Publishing 101 useful resources site.