Many months after reading and hearing about their introduction in the US, portable electronic books are now becoming available in the UK. Franklin’s eBookMan  is available online from bestbuy.com and amazon.com and from some high street retailers, the goReader is available for purchase via their Web site , a variety of ebook reading software can be downloaded to PDAs for free via the Internet, and some Pocket PCs are being sold pre-installed with Microsoft Reader .
This paper places these developments in context by outlining the evolution of the portable ebook from its original conception in the ‘60s through to the models available today, and on to the possible directions the design of these devices may take in the future.
The idea of the portable electronic book dates back to 1968 when postgraduate student Alan Kay articulated the concept of the Dynabook, "a portable interactive personal computer, as accessible as a book" . Considering that this was many years before the advent of the personal computer and the Internet, his idea for a tablet-style computer capable of wireless communication was a visionary one, and more than two decades passed before products matching his description began to appear in the marketplace. Kay went on to work at the Xerox Palo Alto Research Center, developing graphical user interfaces, then at Apple, where his vision of the Dynabook finally transformed itself into reality in the form of the Apple Newton MessagePad, the world’s first PDA. Touch-screen based, the Newton was capable of displaying electronic titles in NewtonBook format, and indeed hundreds of ebooks were produced, but the product line was discontinued in 1998 when leaner, lighter PalmPilots and Handspring Visors entered the market .
During this time, Franklin Electronic Publishers and Sony were busy developing their own concepts of the portable ebook. In 1986, Franklin were the first to enter the market in 1986 with a handheld device containing an electronic dictionary and capable of displaying only one line at a time, followed, in 1991, by an electronic Bible, this time with a four line screen and keyboard.
Also in the early ‘90s, Sony developed the Data Discman , otherwise known as the Electronic Book Player, which played both audio CDs and books on CD-ROM. The Discman was bundled with Compton’s Concise Encyclopaedia, Wellness Encyclopaedia, and Passport’s World Travel Translator and introduced to the American market at a price of $550. The Sony Electronic Book Authoring System  enabled other compatible titles to be created, but this software sold for $9000 and few additional ebooks were ever produced.
Criticised for its proprietary architecture, small screen size, poor resolution and limited multimedia capabilities, the Discman was soon superseded by the Bookman (to be distinguished from the eBookMan) , produced first by Sony and later by Franklin. This weighs 2 pounds, has a 4.5” diagonal screen, and employs cartridges containing a variety of reference materials, from foreign language dictionaries to collections of quotations. These cartridges cost between $20 and $80 and are still available today. Franklin’s other “first generation” portable ebook which can still be found on shop shelves is the Pocket PDR Medical Book System , a small 4.6 oz device with keyboard and monochrome screen, and with a variety of manuals of therapeutics and handbooks of drug interactions available on “book cards”, priced between $30 and $130.
Poor usability in terms of the comfort of reading from such small screens, and the lack of an appropriate content distribution channel, means that the success of these early devices from Sony and Franklin was limited. Most recently, Franklin have launched the eBookMan (see below), a device which attempts to overcome these limitations by providing a larger screen and enabling titles to be downloaded from the Internet.
The arrival of PalmPilots in 1998 marked the widespread availability and uptake of small, powerful and portable computers, and had an enormous impact on the demand for handheld devices. With the technology now available, a market for small devices established, and reading text from small screens growing in acceptance, publishers and entrepreneurs had both the ability and the confidence to begin developing electronic books, and a second generation was born . Like their predecessors, these models of ebooks take advantage of the ability of technology to store multiple titles in a small space, but they also try to provide readers with a comfortable experience by retaining the advantages of the print medium and mimicking aspects of the book metaphor: they are all designed to be used “like a book” by reading black text against a light background on a high resolution screen, larger than that of the Discman or the Bookman, employing “pages” (or sections of text occupying distinct visual spaces) which can be “turned” using buttons dedicated to that purpose.
Nuvomedia, Inc. in Palo Alto, California, were the first to launch their “new wave” ebook at the Barnes and Noble store in New York in October 1998. The Rocket eBook  is a paperback-size device that holds 10 books (4,000 pages of text and graphics), weighs one pound and cost around $270. It has a 4-by-3-inch high contrast screen with high resolution, a number of font sizes can be selected, and it can be customised for left- and right-handed use. The battery lasts for about 20 hours when backlit, and 45 hours without being backlit. The device has a search facility and a bookmarking function. The Rocket comes with a PalmPilot-like cradle that connects to a serial port; titles are ordered online, downloaded to a PC and finally transferred to the reader.
Its closest competitor was the SoftBook  by SoftBook Press of Menlo Park, California. The SoftBook has a leather cover which, when opened, automatically starts up the book. It holds 250 books (100,000 pages), has a backlit, high resolution 7-by-6-inch screen which can display 16 shades of grey and about twice as much text as the Rocket, weighs nearly 3 pounds and cost around $600. Functions such as choosing a title, page turning, bookmarking, underlining and annotating can be performed using touch-screen technology. Its battery provides up to five hours of viewing, but it offers a fast recharge of an hour. Unlike the Rocket, it is completely independent from the PC: content is loaded in an HTML-based proprietary format and downloaded directly to the reader via an internal modem.
The Rocket and the SoftBook were available in the US and Canada, and have now been superseded. Rockets can still be bought in Germany, however, and are still in wide circulation in the US.
Today, the market for portable reading devices is characterised by three main strands: dedicated ebook readers; PDAs and Pocket PCs with book reading software; and hybrid devices which primarily function as ebook readers but also offer some or all of the functionality of Pocket PCs and PDAs.
These are descendants of the Rocket and the SoftBook, built solely for the purpose of book reading. Typically, they are small, lightweight devices (usually with larger screens than PDAs and Pocket PCs) with backlit screens and embedded dictionaries. Often they enable searching, bookmarking and the ability to make annotations, and can either be connected to a PC or contain internal modems so that content can be downloaded from the Internet.
The SoftBook and the Rocket eBook sold less than 50,000 units between them , but the novelty of their design and availability of titles sparked interest and controversy and captured the imaginations of consumers and manufacturers around the world. In January 2000 Nuvomedia and SoftBook Press were acquired by Gemstar eBook Group, and the Rocket and the SoftBook are no longer manufactured.
Figure 1: REB 1200
RCA, through a licensing deal with Gemstar, now manufacture the REB1100  and the REB1200 , which replace the Rocket and the SoftBook respectively. The REB1100 is the cheaper of the two, selling at around $300. It is slightly lighter than the Rocket, has a built-in modem and runs its own proprietary format. The REB1200 retails at $700 and has a large colour LCD screen. The REBs have combined projected 2001 sales of 3 million to 7 million units .
Other companies have joined the market, goReader perhaps being the most notable. The goReader is an OEB compliant ebook reader designed for university students, who obtain textbook content directly from the goReader Web site. The idea behind this device is that it will enable students to carry around all their textbooks for one semester (it has a 5GB hard drive and 32 MB DRAM) in one portable device weighing less than five pounds. Additional features, tailored to the student market, include a built-in calculator, calendar and electronic notepad.
Figure 2: goReader
These are usually smaller than dedicated ebook readers and primarily function as personal organisers. Often they also offer Internet access and word processing, spreadsheet and MP3 playing capabilities. Increasingly, as content and ebook reader software for these devices becomes available, they are now being used additionally to read books. Examples of the software available today include:
Several devices are emerging which cross these previously distinct boundaries between hardware designed especially for reading books, and hardware designed to perform personal organiser tasks, with ebook reading an added functionality. These “hybrid devices” look similar to dedicated readers, with larger screens intended for reading long streams of text, buttons placed for easy turning of pages, and with the usual ebook capabilities such as bookmarking and annotating, but may also contain address books and to do lists, and be used to perform the types of task normally associated with PDAs, such as email reading, Internet browsing and MP3 playing.
Figure 3: hiebook
Examples include the eBookMan, relatively well priced at $130 to $230, currently the only device of its kind easily available in the UK and which supports audio files and contains an address book and a to do lost; the hiebook , with a large touch screen, which has emailing capabilities; and MyFriend , “your ideal companion for working, learning and having fun”.
The co-emergence of these three groups of portable devices on which electronic books can be read indicates that the ebook market is still in its infancy and very much in a state of flux. Until recently, the design of such products has been in the hands of developers and manufacturers; as they become increasingly available, the future development of portable electronic books will be driven more by demand and user response. Of course, the availability of content will play a key role in determining which devices succeed in the medium to long term (the devices are useless unless content is readily available), and the Open eBook Forum  has established standards for representing the content of electronic books which enable compatability across formats and, therefore, hardware.
In terms of the future physical design of ebooks, the current trend towards the convergence of hitherto discrete technologies has been well documented:
“Today, the CE industry, as it becomes digital, is in the midst of a new wave of change. The different worlds of television, telephone and data processing are beginning to share similar technologies and are starting to overlap. This technological "convergence" spurs an array of other convergence moves in products, markets and businesses.” 
Technological consumers of today demand convenience and economy of space from the products they buy . Following this logic, of the three strands of portable electronic books outlined above, PDAs and Pocket PCs or hybrid devices which perform a multitude of functions in addition to book reading will prove most popular: why carry around one device for reading books and another for diary keeping, when both activities could be achieved using just one unit?
This process of convergence may even give rise to new relationships between technologies. Although electronic paper  - a prototype of which was recently developed by Bell Labs and E Ink Corporation and which will show electronic text on thin, flexible, plastic sheets that look and feel like paper and which can be instantly updated via wireless technology - is being touted as the next phase in the evolution of ebooks, Clifford Lynch notes that if a display of this quality can be used as an ebook reader, then it can also be used on a general purpose laptop computer, and ebook readers will face competition, in terms of price and functionality, from the next generations of laptops .
Bundling together the functions of book reading and game playing in one device has also been suggested as a sensible and attractive combination. For many, reading books and playing computer games are leisure activities, and today’s portable games consoles place emphasis on weight and screen quality and size, just as portable ebooks do. In fact, a Game Boy Book Reader, written in assembler, has been developed in the UK by MQP Electronics, to allow out-of-copyright classic book texts to be read on the Game Boy screen .
However, there is also a strong case for the survival of devices which are dedicated solely or primarily to the purpose of book reading. The act of reading a book is arguably unlike any other use to which handheld devices can be put, in that it is a highly personal and involving activity about which readers feel very passionate. Moreover, it gives rise to a unique set of design requirements which cannot necessarily be served by hardware intended to perform a multitude of other functions. A host of expectations derived from the print medium come into play, including the need for intuitively placed buttons for page turning, and to be able to “open” a book with the minimum of effort. Issues such as screen quality and the comfort of holding the device in your hand, while important for all PDAs and Pocket PCs, become paramount when reading a book, and can sometimes give rise to contradictory requirements. For example, a device which is small enough to fit into a shirt pocket may have a screen of sufficient size for diary keeping or note-taking, but may be simply too small for reading texts of any length. That readers feel strongly about the experience of reading books is well known; that they will find specially designed devices which cater singularly for their unique book-reading needs more attractive than general purpose devices, is a real possibility.
The future shape of the portable electronic book is, at least in part, dependant on whether the trend towards convergence applies equally to ebooks as it does to other technologies: do users’ desires for multi-functional devices override the unique set of design requirements which arise when reading text electronically? Moreover, as Lynch notes, ebooks which represent a reconceptualisation of the printed book, “face formidable challenges in their authoring, economics, and acceptance; these are emerging rather than mature forms” .
EBONI (Electronic Books ON-screen Interface), funded under the JISC DNER Programme for Learning and Teaching , is learning about the wants and needs of users of ebook hardware, within the context of Higher Education, through an evaluation of a selection of devices during Summer 2001. The aim is to discover which features facilitate or enhance the experience of reading a book, and which detract. Lecturers and researchers from the University of Strathclyde’s Department of Computer and Information Sciences , and the Centre for Digital Library Research (CDLR)  are participating in the evaluation of a Rocket eBook, a SoftBook, Franklin’s eBookMan, a PalmPilot and a Hewlett-Packard Jornada 548. At the time of writing, this research is still underway, but it is possible to derive a selection of preliminary conclusions based on participants’ comments so far.
That readers approach texts in electronic format with expectations inherited from their experience with paper books has been confirmed in EBONI’s studies to date. As one reader noted after reading a text on a handheld device, “It didn’t feel like I was reading a book. The fact that it was an electronic device rather than a traditional book with a cover and pages somehow seemed to me to take something away from the experience”. Results of EBONI’s evaluations so far highlight the importance of the following aspects of the paper book metaphor:
In addition, one feature of reading a paper book has been identified as capable of improvement by the electronic medium. Some readers feel that the action of turning pages slows down the reading process, and that alternative methods of moving through a book offered by electronic devices, such as turning wheels and pressing keys or buttons, increase the speed at which they read the book. One participant in EBONI’s experiments commented, “In turning a paper page you lose momentum, albeit for a second or two. I didn’t find this at all with the ebook.” Another noted, “The ability to change pages by using your thumb on the wheel meant that you could quickly move through a story without breaking your stride”.
In summary, early feedback from EBONI’s evaluations of portable reading devices points towards the following elements as worthy of attention when designing for usability:
The full results of this experiment and EBONI’s other ebook evaluations will feed into a set of best practice guidelines for the design of electronic textbooks. These will be disseminated to publishers and writers of electronic material, libraries and museums involved in digitising collections and interested parties in the HE community in general. They will also be available from the project Web site , together with an example of a text on which they have been implemented. In the meantime, the project’s progress can be followed at the Web site, or by joining the EBONI mailing list .