EBONI: Designing effective electronic textbooks Free

Ruth Wilson

Electronic books are beginning to appear in the UK marketplace, in an array of shapes and sizes: e-book hardware ranges from small and light to large and bulky; e-book software presents content in a number of formats and offers a variety of features; and books published online differ greatly in appearance. EBONI (Electronic Books ON-screen Interface) (http://eboni.cdlr.strath.ac.uk) is investigating which aspects of the design of these electronic textbooks are most successful in terms of the usability requirements of students and academics throughout the UK. Based at the Centre for Digital Library Research (http://cdlr.strath.ac.uk), University of Strathclyde, and funded under the JISC DNER Programme for Learning and Teaching(http://www.jisc.ac.uk/dner),the project is identifying and comparing the variety of methods which have emerged in the design of electronic textbooks for higher education, in order to determine the most effective way of representing educational material electronically, aiming to maximise usability and information intake by users. The final output of the project will be a set of best practice guidelines for electronic textbook design.

Evaluations

These objectives are being achieved through a series of evaluations of different kinds of electronic textbooks in a number of subject areas. Some examples include:

• 1.

  An evaluation of three textbooks in psychology by second-, third- and fourth-year psychology undergraduates. All three textbooks differ markedly in their appearance, and the study aims to find which styles and techniques are most effective in enabling students to find the information they require, and to record students' subjective satisfaction with each book.

• 2.

  An evaluation of Hypertext in Context by McKnight et al.,(1991). This textbook is being compared in three formats: print; the original electronic version on the Web; and a second electronic version revised according to John Morkes and Jakob Nielsen's (1998) guidelines for "scannability". These guidelines suggest that the usability of Web publications can be increased by up to 50 per cent by altering the appearance of the electronic text so that it uses extra headings, large type, bold text, bulleted lists, graphics and captions. They were implemented in the WEB book experiment with some success(Wilson, 1999), and are being applied again here so that more detailed conclusions can be drawn.

• 3.

  A comparison of a title in geography by second-year geography undergraduates. This is available commercially in three proprietary electronic formats:

• 4.

  • MobiPocket Reader, a universal reader for PDAs and pocket PCs.

  • Adobe Acrobat e-book Reader for reading PDF format electronic books on a laptop or desktop PC.

  • Microsoft Reader, which attempts to recreate the look and feel of ink on paper through ClearType technology which increases the resolution of text by smoothing the tiny spaces between the pixels on a computer screen. Some pocket PCs are now sold pre-loaded with Microsoft Reader.

• 5.

  A comparison of three electronic encyclopaedias: Encyclopaedia Britannica, The Columbia Encyclopaedia, and Encarta. Versions of these are freely available online and differ greatly in the styles and techniques they use to present information.

• 6.

  A study into usability issues surrounding portable electronic books. Five devices are being evaluated by lecturers and researchers at the University of Strathclyde with the aim of determining which physical design elements enhance and which detract from the experience of reading or consulting an electronic book. These are: a Hewlett-Packard Jornada with Microsoft Reader, Franklin's e-bookMan, a Palm with PalmReader, a Rocket e-book and a SoftBook. Note that the Rocket e-book and the SoftBook have now been superseded by the REB 1100 and the REB 1200 respectively.

To ensure that the results of these evaluations can be compared at some level, during the early stages of the project EBONI developed an "e-book evaluation model" which is being implemented to varying degrees by each experiment (Wilson and Landoni, 2001). The evaluation model comprises a number of options for selecting material and participants, and describes the different tasks and evaluation techniques which can be employed in an experiment. These include:

• Retrieval tasks, designed to measure participants' ability to find information in the material.

• Memory tasks, which measure participants' ability to recall information from the textbook.

• Questionnaires measuring subjective satisfaction.

• One-to-one interviews, used to elicit full feedback on selected aspects of the experiment, and to follow leads on additional themes raised by the participant.

• "Think aloud" sessions, which provide qualitative feedback about the participants' cognitive processes, explanations of how they are navigating the test material, and reasons for difficulties.

Emerging results

The results of EBONI's experiments so far can be categorised under two main headings, both of which impact on the usability of e-book interfaces: the on-screen appearance of information, and the look and feel of the physical object or reading device.

Two main themes are emerging as fundamental to usability in terms of the on-screen appearance of e-books:

• 1.

  The legacy of the paper book metaphor, and the wisdom of adhering to this,where appropriate, in the construction of the electronic book.

• 2.

  The different set of requirements arising when the reader interacts with the new medium; in particular, the effectiveness of presenting material electronically in short, scannable chunks rather than a long stream of text. This concept is derived from the work of Jakob Nielsen who suggests that, in order to be a success, an electronic text should not simply mimic its paper counterpart. He believes that the digital medium involves the reader in a different way and that much more powerful experiences can be achieved by deviating from a linear flow of text (Nielsen, 1998).

Specifically, the following on-screen design considerations are emerging from EBONI's work to date:

• Cross-referencing between the pages of a book, between the main text and table of contents, index, footnotes, glossary or references is considered an important property of the printed medium. Readers strongly value the ability to achieve these cross-referencing tasks in an electronic environment.

• In the digital medium, readers expect the typographical sophistication of the printed page, and pagination has to be designed carefully to enhance readability.

• Readers perceive one of the main advantages of presenting educational material in the electronic medium as being the ability to exploit multimedia elements such as video and audio, and interactive elements in the form of experiments and quizzes. Inclusion of elements such as these can increase a reader's "sense of engagement" with the book, enhancing their ability to remember the information being conveyed.

• Readers gain a sense of their place in a printed book via the page numbers and by comparing the thickness and weight of the pages read against the thickness and weight of the pages still to be read. It is important for this"sense of place" also to be present in the electronic medium, and indications of a reader's progress through the book should be accurate and visible.

• Within each page, breaking the text into short chunks improves the scannability of the text. This can be achieved by, for example, interspersing text with images and diagrams and keeping paragraphs short, and by using meaningful sub-headings, indented, bulleted lists, and colour to break the uniformity of the text.

• Readers expect images, diagrams and formulae to be included and to look as visually sophisticated as they do on the printed page. In scientific and mathematical disciplines, it is often necessary to study diagrams and formulae closely and to make comparisons, and this should be taken into account when positioning these items in the text.

So, on-screen design is a crucial factor in the success of electronic books and, for usability to be maximised, expectations inherited from reading on paper must be considered alongside the constraints and capabilities arising from presenting information in digital format.

The second factor affecting e-book usability – the hardware surrounding the text, which enables the user to interact with the book – was the subject of EBONI's research during the summer of 2001 when five portable devices were evaluated by a group of lecturers and researchers. Their feedback points towards the following elements as worthy of attention when designing e-book hardware:

• 1.

  Display technology should be high resolution, with high contrast and minimal glare; lower resolution monitors can cause eye-strain with prolonged use. Backlighting can increase portability, in that it enables text to be read in poor lighting conditions.

• 2.

  Finding the optimum size of e-book hardware is a question of balancing weight, portability and ergonomics against legibility and quantity of text on screen. Small, slim, lightweight devices are easier to hold and more attractive than large and heavy ones; however, users dislike very small screens which restrict the amount of text displayed in any one "page", as they have to turn pages very frequently.

• 3.

  e-book hardware should be designed for comfort (large, heavy devices can be difficult to hold), and the ability to hold a device easily in one hand is considered an advantage. The necessity to use a stylus should be kept to a minimum (they can be awkward to handle, and users worry about losing them).

• 4.

  Careful design of buttons or dials for turning pages can improve this aspect of the paper book metaphor, leading to a smoother, faster transition from one page to the next. In EBONI's evaluations, users of the devices which employ dials commented that they felt they could read faster using this method of page turning. Simple "page forward/page back" buttons are felt to be intuitive, and buttons should be large, as opposed to small and fiddly.

• 5.

  The number and diversity of situations in which e-books can be read can be constrained when devices are delicate, fragile or costly. "You can drop a[paper] book from more than 12 inches without damage", was one participant's observation.

Conclusions

Past and present research highlights a number of elements which should be considered when designing interfaces for electronic textbooks. The "look and feel" of on-screen information and hardware plays a crucial role in allowing users to read and use text in electronic form as much as they do with information on paper.

A full set of best practice guidelines for designing electronic textbooks,incorporating the considerations outlined above, is being compiled by EBONI and will be made available from the project Web site in early 2002. They will be relevant to writers and publishers of electronic material, libraries and museums involved in digitising collections, and interested parties in the HE community in general.

EBONI welcomes feedback at all stages, and readers are invited to join the project mailing list[1].

Note1. For details of how to join the EBONI mailing list, see the JISCmail Web site: http://www.jiscmail.ac.uk/lists/open-eboni.html

ReferencesMcKnight, C.,Dillon, A. and Richardson, J. (1991), "Hypertext in context", available at: http://telecaster.lboro.ac.uk/HiC/HiC.htmlMorkes, J. and Nielsen, J. (1998), "Applying writing guidelines to Web pages", Cambridge University Press, Cambridge, available at: http://www.useit.com/papers/webwriting/writing.htmlNielsen, J. (1998), "Electronic books – a bad idea", Jakob Nielsen's alertbox, 26 July, available at: http://www.useit.com/alertbox/980726.htmlWilson, R. (1999), "The importance of appearance in the design of WEB books", Department of Information Science, University of Strathclyde,Glasgow (MSc Diss).Wilson, R. and Landoni, M. (2001), "Evaluating electronic textbooks: a methodology", Fifth European conference on research and advanced technology for digital libraries (ECDL 2001), Darmstadt, Germany,4-9 September.

Ruth Wilson (ruth.m.wilson@strath.ac.uk)is the EBONI Research Fellow at the University of Strathclyde, Glasgow.