From Interaction to Trajectories

Steve Benford

Mixed Reality Laboratory

University of Nottingham

Desert Rain (1997)

Uncle Roy All Around You (2003)

Fairground: Thrill Laboratory (2006)

Day of the Figurines (2006)

Trajectories

•All four experiences combine interactivity with liveperformance

•They also exhibit complex and extended spatial andtemporal structures

•They are unified by the approach of creating acoherent journey through the experience

•Building on recent studies of interactive exhibits, thesejourneys can be described in terms of trajectories

Trajectories through hybrid space

Mixed Reality Continuum (Milgram and Kishino)

VirtualReality

(Everyday)Reality

AugmentedReality

AugmentedVirtuality

immersion

ubiquity

Our experiencescombine multiple pointson the continuum to formcomplex hybrid spacethrough whichparticipants move

Trajectories through hybrid time

Story time

The temporal structure of theunderlying story world

Plot time

The temporal structure of thenarration of the story

Interaction time

The times at which a participantchooses or is able to interact

Schedule time

The times at which the narrationis made available

Perceived time

The timing of interactions asperceived by the participant

Time as conceived by the author

Time as perceived by the participant

Trajectories through roles

Spectators

Audience

Bystanders

Participants

Street players

Online players

Performers

Actors

Orchestrators

each role followsits own trajectoryand there aretrajectoriesbetween roles

Trajectories through interfaces

•Interfaces aredesigned and alsoarranged to establisha trajectory ofinteraction

Transitions and Traversals

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Role and interfacetransitions

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Role and interfacetransitions

Temporalepisodes

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Role and interfacetransitions

Temporalepisodes

Physical-virtualtraversals

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Role and interfacetransitions

Temporalepisodes

Physical-virtualtraversals

Access to physicalresources

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Role and interfacetransitions

Temporalepisodes

Physical-virtualtraversals

Access to physicalresources

Seams

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Transitions and Traversals

beginnings

Role and interfacetransitions

Temporalepisodes

Physical-virtualtraversals

Access to physicalresources

Seams

endings

Trajectories have to negotiate varioustransitions and traversals during whichcontinuity may be at risk

Negotiating Trajectories

Participanttrajectory

Canonicaltrajectory

Canonical and participant trajectoriesrepresent an author’s ideal journey and aparticipant’s actual journey respectively

Negotiating Trajectories

Participanttrajectory

Canonicaltrajectory

Interactivitydrivesdivergence

Canonical and participant trajectoriesrepresent an author’s ideal journey and aparticipant’s actual journey respectively

Negotiating Trajectories

Participanttrajectory

Canonicaltrajectory

Orchestrationdrives

convergence

Canonical and participant trajectoriesrepresent an author’s ideal journey and aparticipant’s actual journey respectively

Interleaving Trajectories

Multiple trajectories canrepresent different participantsor different applications

Participant ‘red’

Participant‘blue

Interleaving Trajectories

Multiple trajectories canrepresent different participantsor different applications

Participant ‘red’

Participant‘blue

Mutual awarenessand encounterswhen trajectoriescome together

Interleaving Trajectories

Multiple trajectories canrepresent different participantsor different applications

Participant ‘red’

Participant‘blue

Steer trajectories apartto avoid contention orto minimise distractionsand interruptions

Interleaving Trajectories

Multiple trajectories canrepresent different participantsor different applications

Participant ‘red’

Participant‘blue

Pacing involveskeeping trajectoriestogether

Summary of Trajectories

•A trajectory describes a journey through an extended user experienceemphasising continuity and coherence

•Trajectories pass through hybrid structures of space, time, roles andecologies of interfaces

•Trajectories have to cross key transitions including beginnings,endings, role and interface transitions, physical-virtual transitions,temporal episodes, physical resources and seams

•Canonical trajectories and participant trajectories represent authorand participant control and diverge and converge due to interactivityand orchestration

•Interleaved trajectories describe collaborative and/or multi-taskingsituations and address encounters, awareness, separation, pacing andprioritisation