The visual book experiment

The visual book represents a particular interpretation of the electronic book, based mainly on the visual aspects of the real book, its physical features, such as dimensions, thickness, page form and general design style (Landoni, 1997). The visual book is the result of a process of conversion of existing paper books into electronic form and consists of two main components:

1. (1) the visual book generator, which is the authoring system for building the visual book;
2. (2) the visual book viewer, which is the module for presenting the visual book to readers.

The visual book generator system is an authoring tool where it is possible to assemble the visual book as a visual object for the presentation of information from different sources. The basic elements of the visual book system are the visual pages which are visual units of information presented to the reader on the screen. Designers of the electronic publication are completely free to compose the new electronic page in the way they prefer, using a drag and drop interface which lets them browse in an archive of images of text and other components of the book. This version of the visual book authoring system, the visual book generator, has been restricted to handling only images and text but the architecture of this system is open and capable of accepting other forms of information. In this way the visual book authoring system is a flexible tool for testing different presentation styles for the production of electronic documents of high design quality.

The focus in the visual book is on the book’s appearance, interpreted as a way of conveying the cognitive background the reader already has. Book functionalities have been studied in relation to the book’s real use to ensure that information is presented in a natural and familiar way and, at the same time, the reader’s activities are supported in a comfortable environment. An important factor in the visual book development has been the choice of original paper books which should be used for the experiment as not every kind of publication is suitable for electronic translation (Landoni et al., 1993). In the case of the visual book, scientific publications were chosen, as they are used and consulted selectively rather than in their entirety by users. The users of scientific publications were judged to be familiar with computers and could therefore appreciate and evaluate the additional features and functionalities offered by the electronic versions of these books.

The main idea of a visual book is to offer the reader an object as similar as possible to the paper book, replacing its essential physical features such as size and quality with visual ones. Another important principle in visual book design has been to determine which paper book features are more useful and familiar to the reader and to reproduce them in an electronic environment. Particular attention has been paid to the functionalities a visual book could acquire from electronic support and the choice of those which would be most useful and consistent with the specification of the book concept. One of the main advantages of electronic support is its dynamic nature which allows the modification and updating of data in a simple way. On the other hand, a set of functionalities, which are already available in paper books but not currently in their electronic translation, are widely used by conventional readers, such as:

• bookmarks;
• notes on the margins or elsewhere in the text;
• highlighting interesting parts;
• easy access to pages frequently consulted following different clues;
• information about the ratio between pages already read and those remaining;
• control of the reading progress;
• browsing, looking for interesting sections.

All of these have been translated into electronic terms and are essential features of the visual book viewer, as shown in Figure 2.

5.1. Evaluation criteria for the visual book

As noted above the focus of the visual book evaluation has been on the use of the book metaphor interpreted as a graphical simulation of the paper medium which provides an easy to use and powerful interface for information systems, and offers a set of tools which support the reading and consulting process, thus imitating the system produced by the interaction between the reader and the book.

A number of factors were drawn from other experiences in the evaluation of reading processes from computers (Hansen and Haas, 1988; Egan et al., 1991) and were used as the basis for the visual book evaluation. In particular the following three factors were used:

• (1) Sense of directness: is the degree of feeling that changes on the screen are the result of the user’s actions. It is connected with the illusion the user has that the displayed image is a physical object which can be manipulated in the same way as a real paper book. A sense of directness helps a user learn and internalise the interface to a system because every response by the system reinforces the user’s confidence and understanding. In a system with a high sense of directness users can concentrate on the task that is to be accomplished without the cognitive overload of understanding system reactions.
• (2) Sense of engagement: is the level of interest the system induces in the user. The result of a good level of engagement is a high level of concentration that makes users interested in their task. One source of engagement is the fun of seeing the system react and is related to the novelty of the system; tangibility and responsiveness are also responsible for a good level of engagement. Paper has generally a low level of engagement because it is not interactive and is already familiar to users.
• (3) Sense of text: is the feeling a user may have of the structural and semantic structure of the text that is being read, i.e. its spatial disposition. Readers are able to recall the position of text in a paper text (Rothkopf, 1971). This fact connects a semantic entity, the information, with a physical one, which has visual and tactile cues. Factors which can influence the sense of text are the page size, limited legibility and a low responsiveness while scrolling when looking for more text.

The visual book concentrates on the need for readers to have a sense of text, page and directness especially when they are used to consulting paper books and are then presented with their electronic equivalent. Each of the three tasks which were presented to the evaluators (see 5.3) was designed to test the importance of one of these three senses more strongly than the others in order to facilitate the interpretation of the results.

5.2 The users

The choice of the users was made to reflect two general classes: people already actively involved in working with computers, and therefore labeled as computer experts, and people who are not particularly familiar with computers, and therefore labeled as non-computer experts. This is the same convention used in the evaluation of the Hyper-Book (Catenazzi, 1994) and this choice has been made in order to be consistent with the Hyper-Book experiment and to be able to compare the results of the Hyper-Book with the findings of the visual book. However, an additional issue, which became clear as soon as the experiments started, was that it is not just the fact of being or not being familiar with a computer that makes the difference. Previous experience of the Internet plays a very crucial role because of the ease with which people, while browsing the Net, are presented with electronic publications which all share a common hypertext-oriented interface, although this kind of user is usually completely unaware of typographic rules and style in presentation.

5.3. The structure of the experiments

The visual book evaluation consisted of two experiments, one involving a user-oriented group (eight people) and the other with a computer-oriented group (ten people). Each of these groups was given a jogthrough session, a heuristic testing method used for assessing the usability of a system during the design process (Rowley and Rhoades, 1992). This session focused on the visual book and a short introduction to other electronic book models. In order to be consistent with an assumption that the evaluators were experts in the use of the paper counterpart, two different books were used for the two groups, so that the evaluators already knew the content of the book and how to consult and use it. Each jogthrough session consisted of three exercises (tasks) which had to be carried out by the evaluators. The exercises were chosen in order to be of increasing difficulty but inherently soluble for the evaluators and, although each of the exercises was tailored to the specific book chosen for the audience, the types of exercise were the same for the two groups. For each exercise the evaluators had to fill in the evaluation sheet and they were free and explicitly encouraged to express their opinions, comments, criticisms and suggestions. The evaluation sheet used for the visual book evaluation was a modified version of that proposed by Rowley and Rhoades (1992) (see Appendix for details).

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