Exploring potential usability gaps when switching mobile phones: An empirical study
Paper in proceedings, 2007

The study presented explores potential usability gaps when users switch from a familiar to an unfamiliar mobile phone interface. A within-subject experiment was performed in which nine users familiar with Sony-Ericsson T630 and nine familiar with Nokia 7250 performed tasks on both phones. On average, test subjects spent more time on finishing tasks with an unfamiliar phone than with a familiar one. For two of the four tasks, there was a significant difference in completion time between the first-time Nokia users and the first-time Sony-Ericsson users. The tasks of adding a contact to the address book and sending an SMS to a contact in the address book were performed more quickly by new Nokia users than by new Sony-Ericsson users. The subjective difficulty ranking also showed that first-time Nokia users found the new phone easier to use than first-time Sony-Ericsson users did. Hierarchic Task Analysis is used as a potential explanation, and three other theories that relate to these findings are presented: mental models, habit errors, and emotional attachment.


user-centred design

Human Factors


direct manipulation)






user Interfaces

interaction styles (e.g.

Mobile phone UI

usability evaluation

usability problems


Aiko Fallas Yamashita

University of Gothenburg

Wolmet Barendregt

University of Gothenburg

Morten Fjeld

Chalmers, Computer Science and Engineering (Chalmers), Computing Science (Chalmers), Computing Science, Interaction Design Collegium (Chalmers)

The 21st BCS HCI Group conference


Subject Categories

Other Computer and Information Science

Information Science

Human Computer Interaction

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