9 - The readable electronic book

It is now possible to write a high-level functional specification for the electronic book and its user interface. The draft below is not exhaustive and will need considerable refinement and attention to detail during the detailed specification and development process. Most of the findings apply to any document we might wish to read on the screen.

In reality, there may be more than one type of electronic book: there are at least two “sweet spots” for reading. The first is a device that is smaller, more portable, and equates more or less to the printed paperback, except that it will contain a number of books, be able to download new books, and may also have other features such as annotation. It could be a monochrome device.

The second level of device will have color and support for sound, and will take advantage of these and other capabilities to take electronic books beyond the books of today. To succeed, this will have to be done in a careful, planned manner, to ensure that this additional functionality does not destroy readability by degrading the OSPREY effect.

Both levels of device will have much in common.

They will take as input a defined data structure designed to allow automatic formatting of the content.

They will use the screen as a “page” in portrait mode.

They will utilize a reading engine to layout this text according to OSPREY principles.

They may use a single typeface, or a number of typefaces, but these will be carefully chosen (and in some cases, adjusted by hinting and other techniques) for optimum readability on the screen.

New RGB striping font technology will be used to improve the readability of the type. If the lower-level device is to be monochrome, this should be manufactured using a basic color screen but with the color filter left out during the manufacturing process. This will allow high-resolution grayscale to be implemented using the same technique as for RGB color.

Text will be divided into “pages” which will have adequate margins. Pages will be numbered as the text is being formatted. Pages will always have the same number on the same device, and will always be laid out identically.

The user interface will have two modes: browsing and reading.

In browsing mode, the reader will be provided with all the software tools necessary to find a book, purchase or borrow a book, and load a book.

In reading mode, these tools will disappear and the user interface will be very similar to a printed book, permitting only page turns, forward and back, etc. It will provide a means of “backing out” to browsing mode. This mode change will happen automatically and completely transparently as far as the reader is concerned. The decision to open or re-open a book will automatically trigger reading mode.

The OSPREY engine will have a set of harmonic tunings for different type sizes. For example, when the reader wants to read 11point type, the text will be formatted with the correct line length, leading etc. If the reader wants to read, say, 16 point, these settings will all change together to a new “set” harmonically-balanced according to OSPREY rules. Changes will be driven by the reader’s typesize preference alone.

The OSPREY engine will use screen metrics to set the text.

Harmonic tunings will include word- and letter-spacing settings.

Text will be set fully-justified.

To keep spacing constant, text will be hyphenated.

Hyphenation will be done using a dictionary specific to the language of the text. Soft hyphens may be embodied in the text to avoid requirements for the device to have multiple dictionaries.

The OSPREY engine will be capable of handling all typographic features handled by the print publishing engines of today – although the reader will never be aware of the complexity of this process since it will occur automatically.

These features will include: pair kerning (essential for good letter spacing), ligatures, super- and sub-script, small capitals, non-aligning numerals, etc. It may be necessary to implement this by integrating the OpenType Services library.

The engine will be aware of text at the paragraph, page and chapter level and will be capable of widow and orphan control (by adding an additional line to the previous page).

The two-page spread may be one aspect of the printed book that really is merely an artifact of the means of production, i.e. if we have a sheet of paper, it makes sense to print on both sides. But anyone who has tried reading in bed will quickly realize its disadvantages. Most books do not use the spread; perhaps it will be retained only on larger displays, more likely it will go the way of hot-metal typesetting.

9.1 - Alternatives to OSPREY

There are many possible alternatives to Osprey. A number are listed below. The reader will see that all have either been specifically dealt with earlier in this document, or are ruled out on general principles.

• Automatic scrolling of text at reader-adjustable pace
• Scrolling magnifier to focus on individual lines
• Rapid Serial Visual Presentation (single words flashed on the screen one at a time at high speed)
• “Square span” formatting (formatting type in two-line blocks rather than in single serial lines)
• Digital paper
• Paragraph highlighting
• Sharp focus on a single line at time, moving at reader-adjustable pace
• Horizontal instead of vertical scrolling
• Color highlighting of words at reader-set pace
• Display individual words at larger size at reader-set pace
• Presentation of text one paragraph at a time at reader-set pace
• Single line of text, scrolling horizontally at reader-set rate
• Scrolling at pace set by watching reader eye movements
• Rapid Serial Visual Presentation at pace accelerated by reader
• No margins, use full screen width
• Indent every second line
• Set text ragged right
• Use sans serif for text because “it’s more readable on the screen”
• Animation
• Words fly on to screen one at a time
• Words dissolve onto screen
• Lines appear one at a time at reader-set pace
• Paragraph you’re reading is in readable text, paragraphs before and after are grayed out (page automatically scrolls at reader-set pace, or manually scrolling with Intellimouse)
• Set text all caps
• Build page one word at a time
• Set text in large size, i.e. 18 point or bigger