Gul Agha, Robert B. Allen, Michel Beaudouin-Lafon, Adolfo Guzman-Arenas, Wendy Hall, Carol Hutchins, Mary Jane Irwin, Keith Marzullo, M. Tamer Ozsu, Mary Lou Soffa

SUBSCRIPTIONS

Various subscription rates are available; please see the interactions website at http://interactions.acm.org/subscribe.php for more information.

Single copies are $13.00 to members, $20.00 to nonmembers. Please send orders prepaid plus $4.00 for shipping and handling to ACM, General Post Office, P.O. Box 30777, New York, N Y 10087-0777 or call +1-212-626-0500. For credit card orders, call +1-800-342-6626. Order personnel available 8:30-4: 30 EST. After hours, please leave message and order personnel will return your call.

CHANGE OF ADDRESS

acmcoa@acm.org

For other services, questions, or information: acmhelp@acm.org

INTERACTIONS ADVISORY BOARD Jonathan Arnowitz, Apala Lahiri Chavan, Elizabeth Dykstra-Erickson, Shelley Evenson, Robin Jeffries, Kun-Pyo Lee, Aaron Marcus, Lisa Neal, Ian McClelland, Raquel Oliveira Prates

SPECIAL THANKS TO OUR DEPAR TING EDI TORIAL BOARD

ACM Copyright Notice

Copyright © 2008 by Association for Computing Machinery, Inc. (ACM). Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and full citation on the first page. Copyright for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or fee. Request permission to publish from: Publications Dept., ACM, Inc., Fax +1-212-869-0481 or email permissions@acm.org

For other copying of articles that carry a code at the bottom of the first or last page or screen display, copying is permitted provided that the per-copy fee indicated in the code is paid through the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, +1-978-750-8400, +1-978-750-4470 (fax).

Figure 2. Using a laptop on the corner of a beverage trolley [ 4].

the present-day multidevice environment implies having additional tasks of transferring operation and data across devices and places. For this, users must be conscious of the various technological “seams” working counter to their goals, such as discontinuities in connectivity or electricity.

The workers exhibited intricate knowledge of the supportive and constraining factors particularly in local and frequently visited places. For other kinds of trips they had to choose strategies that addressed uncertainty over possible seams.

Some workers used server backups that they knew they could access in a place with a wireless connection. When anticipation was not possible or desired due to cognitive cost, users disciplined themselves to take backups of important files on their smartphone, for example, when going on a longer trip. If, for some reason, the laptop

was not available, a product presentation would then be available from the smartphone. Such “just in case” backup devices were taken along also on shorter trips within the office, where there was a possibility of encountering an important colleague.

The workers also employed a variety of strategies to share documents between their devices. Each device provides different affordances to access information, and users were sensitive to those. Some users did “data mirroring,” copying files to the smartphone for read only. Two-way synchronization, updating file versions on each device after each update, was the most laborsome strategy as it required its adopter to discipline herself to do it, for example, in the mornings. When upcoming situations were predictable, a worker could get by with opportunistic synchronization of a single device.