Picture of neon light reading 'Open'

Discover open research at Strathprints as part of International Open Access Week!

23-29 October 2017 is International Open Access Week. The Strathprints institutional repository is a digital archive of Open Access research outputs, all produced by University of Strathclyde researchers.

Explore recent world leading Open Access research content this Open Access Week from across Strathclyde's many research active faculties: Engineering, Science, Humanities, Arts & Social Sciences and Strathclyde Business School.

Explore all Strathclyde Open Access research outputs...

Enhancing KLM (Keystroke-Level Model) to fit touch screen mobile devices

El Batran, Karim Mohsen Mahmoud and Dunlop, Mark (2014) Enhancing KLM (Keystroke-Level Model) to fit touch screen mobile devices. In: Proceedings of the 16th International Conference on Human-Computer Interaction with Mobile Devices and Services. ACM, pp. 283-286. ISBN 978-1-4503-3004-6

[img]
Preview
PDF (Karim MHCI Final Camera Ready)
Karim_MHCI_Final_Camera_Ready.pdf - Accepted Author Manuscript

Download (660kB) | Preview

Abstract

This short paper introduces an enhancement to the Keystroke-Level Model (KLM) by extending it with three new operators to describe interactions on mobile touchscreen devices. Based on Fitts’s Law we modelled a performance measure estimate equation for each common touch screen interaction. Three prototypes were developed to serve as a test environment in which to validate Fitts’s equations and estimate the parameters for these interactions. A total of 3090 observations were made with a total of 51 users. While the studies confirmed each interaction fitted well to Fitts’s Law for most interactions, it was noticed that Fitts’s Law does not fit well for interactions with an Index of Difficulty exceeding 4 bits, highlighting a possible maximum comfortable stretch. Based on results, the following approximate movement times for KLM are suggested: 70ms for a short untargeted swipe, 200ms for a half-screen sized zoom, and 80ms for an icon pointing from a home position. These results could be used by developers of mobile phone and tablet applications to describe tasks as a sequence of the operators used and to predict user interaction times prior to creating prototypes.