The legibility of sans serif typefaces : An experimental and comparative study

Abstract

Studies in the field of legibility research date back more than one hundred and ninety years. Typographers, psychologists, oculists, physiologists and educators are amongst those. who have done research and have written about legibility and related fields of reading research. These researchers provided valuable information about factors of legibility. As early as 1878, Professor Javal of the University of Paris established that a reader's eyes move along a line of print in a series of quick jerks (Spencer 1969:13). This was contrary to the popular belief that a reader's eyes move along a line of print in a smooth sweep. Javal called these quick jerks saccadic movements. Apart from eye movements, other factors viz. illumination, colour, heart rate, blink rate, visual fatigue and typographical factors were investigated. It is especially legibility studies involving typographical factors that are of interest to the designer and typographer. Research has provided guidelines concerning the legibility of telephone directories, newspaper headlines, backbone titles, line spacing, the length of a line of type and electronic text, to name but a few. Graphic design is a discipline that is intrinsically linked to art, commerce and communication. It can cover everything fiom a simple image that conveys a single phonetic sound to a major component in a public relations programme or advertising campaign. In its simplest form the function of graphic design is to persuade, inform and to identify (Hurlburt 1981 :22). Different techniques and mechanical processes are used in the design process to achieve a certain goal and are normally not seen as ends in them self. Photographs, letters, colour, and hand or machine generated images are all components used by designers in the design process. Typography, one of these components, can be regarded as the most used and sometimes misused element in the graphic design process. Typography is used in all aspects of visual communications, and in conjunction with appropriate images, can convey a very strong and precise message. Gottschall (1989:1) defines typography as a vital element th.at makes electronic and printed communication more effective and efficient. Typography forms an integrating part in most facets of visual communication, whether it be purely functional or aesthetic in nature. Legibility research is, amongst others, involved in establishing how orthographic material can be deSigned and applied to solve typographical problems. Miles A Tinker, an internationally recognised authority on legibility of print, discusses the findings of past studies as well as his own in his book: Legibility of Print. Some relevant aspects are: * * * Italics are read somewhat slower than normal upright romans. Visibility and perceptibility at a distance does not show any agreement between the legibility of a type face and speed reading tests. Legibility is improved by more than seven per cent when indenting the first line of a paragraph (Tinker 1963:64+65+127). Results of Tinker's studies have provided material for seven books and nearly two hundred publications. Tinker is also named by Zachrisson as one of the most prolific writers on the subject of legibility (Zachrisson 1965:34). In another interesting study a computer was used to simulate the neurological structure of the human visual system. A digital computer model of human visual processing was applied to characters with and without serifs. In the discussion the researchers concluded that serifs were important and useful in the perception of small 1 individual characters (Robinson, Abbamonte & Evans 1971 :359). With the arrival of computers and electronic text, some of the legibility research shifted towards this field. Foster and Bruce (1982:145) conducted experiments to determine how easily upper cases should be read on a user's television screen compared with lower case characters. The field of legibility research has greatly been enlarged since the arrival of the microchip. Hartley (1987:1 3) argues that much of the research on printed text is relevant when designing electronic text. Owen (1991 :224-230) speculates that the traditional rules of typography will become redundant in the design of electronic magazines. Type can move, change colour, or flash to emphasize a point or to get attention. Electronic magazines are designed with a computer, printed on compact disks, and read from a visual display. Text, animation, video, sound, photographs and illustrations are synthesized into a complex system, from which information can be retrieved to be printed, read, or listened to. Two major obstacles associated with electronic magazines are the expensive hardware in delivering the magazine, and the poor legibility of visual display units especially with small2 typefaces. Researchers have calculated that an office worker must spend between sixty thousand and eighty thousand hours reading documents, books and instructions as part of his job during his career (Meyer 1987:7). Legible documents and books are not only important for office workers, but must be a priority in educational reading material. A tertiary student doing a three year course may have to read between three and ten million words3, depending on the particular subjects during the study period. The personal preferences of the printer and other aesthetic reasons must thus be secondary to the legibility aspect of such material. Research findings of psychologists, educators and typographers have provided valuable information about factors of legibility. This information can now be used by publishers and printers to design and manipulate typographical matter to make reading material legible, inviting to read, and to communicate more effectively. Knowing the factors that diminish legibility, Graphic Designers can also decide how much legibility can be sacrificed for the sake of visual impact and aesthetic considerations.