Salience, Focus and Bandwidth

A centre of expertise in digital information management

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UKOLN is supported by:

Salience, Focus and Bandwidth

Emma Tonkin – Research Officer

Strathclyde Workshop on Distance Conferencing – 22nd October 2009


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Why remote participation?

• Simple premise:

Travel costs £money, £time and £patience

Remote participation

= Cut down on travel

=> Cheaper, faster, less irritating?


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Really?

• Remote access has penalties

• Limited opportunity to interact/contribute

• Sense of presence limited – doesn’t feel like being there

• ‘Incidental’ interactions limited – doesn’t work like being there


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Plan…

I will discuss:

1 Brief review of factors

2 Scenarios + Experiences

3 Some of our research in the area


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Factors

• All the obvious questions:• What? (are you trying to achieve?)• Who? (will be taking part?)

• How many people? • What are they used to?

• How much? • Money – equipment – bandwidth – time?

• How best to emulate and support?


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User-centered

• Participant buy-in is vital

• How good is the user experience?

• Obligatory pseudo-formula:

€

Opt rp = Funcsemulated relevance +immediacy +presence( )

cost proc * cost hw * cost sw * bandwidthreq( )


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Relevant theory from CMC

• Cues filtered out – is CMC poorer, because [non-verbal] cues aren’t transmissible?

• Cues filtered in – despite the lack of inherent [non-verbal] cues, people will find a way?


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Scenarios

• Conference keynote/paper presentation

• SIG/board meeting

• Social conventions and etiquette:• Well-understood for each scenario

• Potentially easier to support than arbitrary interactions!


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Conference keynote: rough rules• During presentation:

• Watch quietly, even if you disagree (but it’s ok to mutter darkly to your neighbour)

• After presentation:• Signal intent to ask question to session

chair (who explicitly directs focus of audience attention)

• When asked, ask question; discuss.


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Problems for remote viewer

• Boring video streams: Not enough detail, too few cues to guide gaze – faded into background

• Some nuances are lost

• No sense of presence; no incidental interaction

• Signaling intent to contribute


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Strategies (1)

• Use low-bandwidth channels (twitter, irc, chat) for external contributions

• Alter conventions for the chair to accommodate remote participants

• Direct gaze through video stream; qualitatively appears more immersive


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Strategies (2)

• Obvious approach: improve quality of transmitted data

• Problem: typically taken to mean ‘higher resolution video’

• Much more expensive. • Most additional data irrelevant, so

filtered out – by viewer! (visual attention)


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Strategies (3)

• What really makes a difference?

• In our case, we found: • High-quality audio*• Relevance of data transmitted; shot,

focus, framing… camera directs interpretation?

• Simple mechanisms for contribution• Fielding social s/w: twitter, etc.


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* For certain definitions of ‘high quality’

• Psychoaccoustic/psychovisual modeling• Perceived quality… depends on perception


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Further aside about audio…

• ‘Cocktail party effect’ – focusing listening attention; source separation

• Permits us to locate & focus attention on a speaker; as accurate as visual localization, but less efficient

• Required info to achieve this is difficult to retain – but very important


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Board meeting: rough rules

• Session chair controls discussion, explicitly directs attention

• Signal intent to contribute

• Meeting minutes taken by nominated individuals; actions identified, declared during discussion


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Problems-remote participant

• Cues and signals

• Gaze/attention (what’s so funny? What are we looking at/talking about?)

• Identity of participants; visual name tags?

• Fault-tolerance: Time zone, jet lag and burnout rate

• Handling language difficulties

• Bandwidth limits


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Strategies (1)

• Build effective conventions between chair and remote participants

• Create fault-tolerant procedures• Circulate notes/actions within minutes • Take turns to complete tasks, so that

departure of one participant is minimally disruptive


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Strategies (2)

• Focus on what matters:• Video dispensable, given desktop

sharing or even async file sharing• High-quality audio is very important• Back-channel enables informal

discussion between participants, and can mediate requests to contribute


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Research

• Best use of limited bandwidth/dev time in various contexts

• What data to collect/use/represent?

• How to represent it?


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Services shared by local and remote participants• Long tradition of hackery –eg. graffiti

wall (bluetooth & web), etc.

• Cheap, fun, simple to set up – but little active interaction sparked as a result


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Conceptual/domain model development scenario


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Usual solution - committee

• Coffee in, specification out

• Goal: shared reference, ‘common ground’

• But: Expensive, limited attendance

• CMC problem. Multi-touch – Where should I be looking? What just changed? Is someone else about to edit what I’m looking at?


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Strategies

• Versioning/diffs

• Simplified visualisation – remote user relative position; distance from screen

• Audio significant; conversation analysis a useful tool in eliciting design issues.


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Discussion

• Smarter hardware, software, etc.• collect relevant, pre-filtered information• Cheap to transmit• But how easy is it to interpret?• Prior work - reaction times to filtered

data can be very fast. Significance+ equivalence of data must be taught, learned, ’intuitive’


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Overall Conclusion

• More detailed data not necessarily better• Getting the right data

• Lots of design time goes into figuring out which data matters most

• Representation may differ significantly from initial form of information

• Hearing gaze and seeing speech? – ambient + intuitive


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Conclusion (2)

• Handy buzzword list:• Emergent, self-organising, etc…• Agile, user-centred design.

• Imagination is free


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Comments, questions, rotten tomatoes?

Salience, Focus and Bandwidth

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