Visual Interfaces: Moving from Paper to Large-Screen Visual Display Units to Small-Screen Visual Display Units Lawrence E. Burgee Towson University 8000 York Road Towson, Maryland 21252-0001, USA [email protected] Abstract This research paper serves as a literature review on visual interfaces as we move from paper to large-screen visual display units to increasingly popular and functional small-screen visual display units. For more than 600 years, paper has been the predominant visual interface used when completing information retrieval tasks. Paper use is deeply rooted in our culture and has had a profound impact on the development of modern-day society. Visual display units gained wide acceptance in the 1970s and are the predominant user interface for computer systems. When visual display units became popular in business environments during the early 1980s, it was found that replacing paper documents with visual display units does not adversely affect the comfort and morale of office workers. However, current computer screens lead to a reading speed that is approximately 25% slower than reading from paper. Many new wireless personal digital assistants and cellular telephones have Internet connections and Web browsers that allow users to undertake information retrieval tasks using small-screen visual display units. Wireless and lightweight handheld devices with small-screen visual display units are becoming more popular as the quality and readability of the screens approach the brightness, resolution, and contrast of paper. 1 Introduction This paper examines the evolution of visual interfaces from the introduction of paper several hundred years ago up to today’s electronic visual display units. This research paper serves as a literature review on visual interfaces as we move from paper to large-screen visual display units to increasingly popular and functional small-screen visual display units. 2 The Paper Interface For more than 600 years, paper has been the predominant visual interface used when completing information retrieval tasks (particularly reading tasks). Paper is inexpensive, familiar to users, easy to load with content via a printer, easy to copy, distribute, and secure (physical lock-up), and the content has a very high resolution, typically 600 dots (pixels) per inch or greater. Thousands of years prior to paper, Egyptians wrote hieroglyphics on papyrus, the Chinese mastered landscape painting (incorporating symbolic text), and the Greeks painted text and graphics stories on vases and other materials (Bolter, 1993). There are several drawbacks to using paper in today’s information-based environment. It is a fixed and passive medium where contents cannot be easily manipulated by hand or processed by machine. It cannot easily be used to take advantage of modern methods for manipulating, distributing, filing, and processing information such as that which can be done by computer application software and Internet connectivity. The speed of distributing paper- based documents is extremely slow when compared with eMail and Web-based document publication in which documents can be seen around the world within seconds of being placed on Web sites. The use of scanners and fax machines is declining as more documents are stored and distributed in electronic formats (Johnson, Jellinek, Klotz Jr., Rao, & Card, 1993). Despite the disadvantages, paper use is deeply rooted in our culture and has had a profound impact on the development of modern-day society. Strassmann contends that paper-based documents will survive as long as institutions deeply rooted in traditions of an agricultural society continue to operate (Strassmann, 1985). Business professionals spend about 60 percent of their time handling the vast quantity of paper flowing into their office daily (Warnock, 1991). However, paper remains the most popular document medium and is likely to remain so for some time (Plume, 1988) because of its credibility (“put it in writing”), tangibility, ease of handling, portability, and compatibility will all imaging devices, such as fax machines, copiers, printers, and scanners (Lui & Stork, 2000). Paper has several physical and visual features which provide context and reference points for the pieces of text that help in the understanding of the text (O'Hara, 1996). There are social implications to the heavy use of paper in today’s world. As we move to an environment where more people read from digital screens, those who expect new technologies to immediately change how we function often forget to take into account the social-material complex of which technologies are only a part of (Williams, 1974). Emerging technologies can solve problems, but they also create dilemmas involving social, cultural, organizational, and human factors (McKnight, 1997; Olsen, 1994). Despite the enormous popularity of personal digital assistants (PDAs) and mobile computing technology, paper usage in the U.S. continues to increase (Schilit, Golovchinsky, & Price, 1998). Of total paper production, the percentage of paper used for printing and writing increased by 13% from 1970-1997. Almost 94% of all business information is still recorded on paper, with an estimated 2.4 billion new sheets placed in paper file folders daily. Sales of paper books continues to grow and library circulation continues to increase, suggesting that people still rely heavily on paper for much of their reading activities. A shift is occurring from print-copy-distribute to distribute-view-print along with a shift from centralized to decentralized printing. In one study Olsen found that 63% of those interviewed preferred to annotate or underline articles as they read them (Olsen, 1994). Many readers are not comfortable reading long documents on a screen. One cannot spread out pages of a large document while reading. The long-standing practice of maintaining file folders of printed materials, arranged by topic, remains popular in the electronic age (Lui & Stork, 2000). One of the crucial properties of paper documents is fixity. Fixity refers to the fact that once a document is printed on paper it cannot be changed unless replaced by an updated version. A printed book remains the same from the publishing date into the distant future, but much of what we view on Web pages changes almost daily. Paper is stable, permanent, static, inactive, and rigid, while digital documents are characterized as unstable, impermanent, dynamic, active (interactive), and fluid (malleable and changeable) (Levy, 1994). Bolter contends that we are moving progressively from the fixed world of paper to the fluid world of digital documents (Bolter, 1991). Digital documents, particularly Web pages, lack stability of text as well as the tactile and visual cues available with paper- based documents. This affects the ability to manipulate a digital document and to develop a sense of text, which is important not only for navigation but also for comprehension (O'Hara, 1996). By sense of text we mean the feeling a user may have that he/she has a good grasp of the structural and logical arrangement of the text, which can be enhanced by fixity (Hansen, 1988). With respect to paper documents, Colley supports global coherence in that a text must have a consistent theme and be structured in a sensible sequence (Colley, 1987). 3 Large-Screen Visual Display Units The visual display unit (VDU) is defined as the visible and usable area of a visual medium. Various synonyms for VDU appear in the literature such as cathode ray tube (CRT), visual/video display terminal (VDT), computer screen, etc. (Mills & Weldon, 1987). Vision is the most important of the five senses and VDUs are a critical component in a human-computer interface (Faulkner, 1998). Most users are not concerned with the technological aspects and underlying architecture of computer systems (particularly in the age of the Internet) and to them what they see on the VDU "is" the system (Norman, 1986). For this review, VDU will mean “large-screen visual display unit”, which in general would refer to a screen having a diagonal measure of 10 inches or greater. The CRT has been the dominant technology for many years. A stream of electrons is emitted from an electronic gun and focused and deflected by an electric field onto a phosphor-coated screen which glows at the point of contact with the electrons (Foley & Van Dam, 1982). Flat-panel displays are smaller in form than CRTs and are typically liquid-crystal displays (LCDs), plasma panels, or electroluminescence devices (Downton, 1991). VDUs gained wide acceptance in the 1970s and are the predominant user interface for computer systems (Shneiderman, 1998). Substantial technological developments with computers and VDUs during the 1970s led to the prediction of a paperless society with in a short period of time (Lancaster, 1978) which has not come to fruition. VDUs have matured from the initial low-resolution black and white displays to today’s larger and somewhat higher- resolution color displays. Newer displays are also available in a wide range of screen sizes and formats. Due to tremendous price reductions and advancing technology over the past few years, flat-panel LCD monitors have now become more popular then CRT displays and account for the majority of monitor sales (Greenemeier, 2003). The big advantage of LCD monitors over CRT monitors comes from their greatly reduced size. LCDs also are preferred to CRTs because they reduce eye strain in that they do not flicker like CRTs. CRTs are “painted” hundreds of times per second in a process known as refresh. Human eyes can detect flicker in larger CRTs with slow refresh rates and this can bring on headaches and fatigue (Thompson, 1984). When VDUs became popular in business environments during the early 1980s, it was found that replacing paper documents with VDUs does not adversely affect the comfort and morale of office workers (Starr, Thompson, & Shute, 1982). However, current computer screens lead to a reading speed that is approximately 25% slower than reading from paper.