Usability of enlargement methods: How enlargement method influences the amount of scrolling actions needed to read publications

Abstract

The two methods to enlarge text are: Geometric magnification (ZOOM) implemented with lenses, CCTV systems and Screen Magnification Systems, and Lexical Enlargement (WRAP), text enlargement with word wrapping that is implemented with software like word processors and web browsers. WRAP uses the lexical structure of language to wrap words. This paper will show that it takes many more scroll actions to read with ZOOM than WRAP whenever the ZOOM requires horizontal scrolling. Since all scrolling is overhead to the task of reading, ZOOM with horizontal scrolling is much less usable for reading text. Though costlier in scrolls than normal reading (27 to 1), WRAP is even effective at 84-point font when viewed on a 13-inch laptop. ZOOM at 700% enlargement requires 98 times more scrolls than normal reading.