Simon Holland on Direct combination

Its a principle

From a pervasive point of view.

Lots of tiny devices ( ipod/mobile phone).
 Get devices to talk to each other - from an HCI point of view.
Lots of versions of software. Diffrent software

Resource-poor user interfaces
   - Small screens
Minimal attention situations
  - Walking

Standardising protocols - problems with combinatorial explosion.

Principle of direct combination 1999

Use two objects to list common subsets of actions that can be used on them both.
Traditional user interface begins with objects and versbs click on X then select action Y.
User selects N objects - you see list of actions common.

Expand selection out to include remote selection ( say via interface )

Not objects but roles -( is a role like an interface ?)

nasa tlx workload scale
nasa tlx task load scale


previous work


Pick and drop Rekimoto - speical case of DC
InfoStick Kohtake
DataTies Rekimoto