List of Figures

• The PARCTAB mobile hardware
• The PARCTAB transceiver
• Format of the data fields for a link-layer IR packet (lengths in bytes).
• The Unistroke alphabet
• A screen from the PARCTAB Arbitron application
• A screen from the PARCTAB locator application
• The PARCTAB system architecture
• Format of IR packet data payload as used by the request/reply protocol (lengths in bytes)
• The path taken by a T-RPC call made from an application to a tab.
• The top-level screen presented by the default Shell
• Histogram showing the number of invocations for each application (not including the shell or tshell) expressed as a percentage of the total invocations of these applications during the test period. Normalized results only count one invocation per day per user to remove distortions that might arise when users experiment with an application several times during a brief period. Applications that might normally be invoked several times a day suffer under this measure.
• Histogram showing the total interaction time by users for each application in the tab system during the 3 month test period (not-including the shell, 1273 minutes, and the tshell, 1081 minutes).
• Graph showing the percentage of application interactions that were under a given time during the test period.
• Histogram showing the number of users against their total interaction time divided into 20 equal divisions.
• Histogram showing the total interaction time for each user in seconds split between three location types: a user's own office, a common area, a hall or another person's office.
• Histogram showing the total interaction time by all users for each of the three general areas: a user's own office, a common area, a hall or another person's office.