Investigating touchscreen typing: the effect of keyboard size on typing speed

Abstract

Two studies investigated the effect keyboard size has on typing speed and error rates for touchscreen keyboards using the lift-off strategy. A cursor appeared when users touched the screen and a key was selected when they lifted their finger from the screen. Four keyboard sizes were investigated ranging from 24.6 cm to 6.8 cm wide. Results indicate that novices can type approximately 10 words per minute (WPM) on the smallest keyboard and 20 WPM on the largest. Experienced users improved to 21 WPM on the smallest keyboard and 32 WPM on the largest. These results indicate that, although slower, small touchscreen keyboards can be used for limited data entry when the presence of a regular keyboard is not practical. Applications include portable pocket-sized or palmtop computers, messaging systems, and personal information resources. Results also suggest the increased importance of experience on these smaller keyboards. Research directions are suggested.

ThumbSpace: Generalized One-Handed Input for Touchscreen-Based Mobile Devices

“…Parhi et al [22] investigated the effect of target size on input accuracy when operating a PDA one handed with the thumb. Previously, others had determined appropriate target sizes for pen-based interaction on mobile touchscreen devices [19], and index fingers for interaction on desktop-sized displays [9,28], but pens and index fingers are smaller than thumbs and their use scenarios differ from the mechanic constraints of holding the screen with the same hand used for interaction.…”

The effect of psychosocial stress on muscle activity during computer work: Comparative study between desktop computer and mobile computing products

“…For instance, a small screen might induce visual demand that makes the user experience visual strain and tiredness [36,37,39] and a small keypad might require user concentration and precision [36,39]. Furthermore, a smaller screen might produce larger error rates and decrease satisfaction [40]. In addition, a small screen might limit the information that can be obtained by the user, especially via video or text [41,42].…”

A novel concept of a wearable information appliance using context-based human–computer interaction

“…Horizontal scroll bars should be avoided with a mobile device in any case [16]. Using a keyboard, for example to fill patient records, is also a problem because it is difficult and slow to type text with a small touchpad keyboard [18]. A better approach could be to use the device as a dictating machine and later write down the information using a standard computer keyboard.…”