CMU MHCI - GM Network Project19 May 2004 ROADCASTING GM Car Network Project Jim Garretson Whitney...

CMU MHCI - GM Network Project 19 May 2004

ROADCASTING

GM Car Network Project

Jim GarretsonWhitney HessJordan KanarekMathilde PignolMegan Shia


ROADCASTINGOverview

Service DesignHigh-level interaction

Scope

Scalability

Design RationaleLightweight interaction

Search vs. Browse

XM Expert Analysis

Implementation Details

Future Plans

Agenda


ROADCASTING

Service for cars in 2010 that uses ad-hoc networking to make radio collaborative and more engaging.

Overview


ROADCASTING

More than just the most popular songs:

commentary from cars close to you

be your own DJ

automatically play the songs that everyone tuning in will like

Overview


ROADCASTING

Every GM car with Roadcasting

can receive Roadcaster stations and influence the songs played (within limits set by the broadcaster)

has the ability to broadcast songs to other cars with Roadcasting

Overview


ROADCASTINGOverview


Scope

Scalability


Search vs. Browse

XM Expert Analysis


Future Plans

Agenda


ROADCASTING

Example scenario.

Service Design


ROADCASTING

Every broadcaster has three levels of involvement:

Managed - broadcaster determines what is played and when

Guided - broadcaster determines what is played with input from the audience

Unmanaged - broadcaster is not active and the collective audience chooses what is played

Service Design: High-level interaction


ROADCASTING

Every listener has two levels of involvement:

Active - listener votes for songs to be played

Passive - listener does not vote (but still influences the station through his/her profile)



ROADCASTING

In Managed and Guided modes, no votes are sent out to the audience

In Unmanaged mode, prompts for voting are sent out to the audience and Active listeners determine the next song played.



ROADCASTING

We have limited the scope of our development to service and interaction design. We will not be addressing:

broadcasters

how they select individual songs to be played

how they might find music on the network

how they might broadcast other media (video)

listeners

how they manage multiple drivers/profiles

how XM, FM and Roadcasting cooperate

Service Design: Scope


ROADCASTING

When a station has no listeners, the station selects music based only on the broadcaster’s preferences.

When a station has one listener, the station recommends music based on both the broadcaster’s and listeners’ preferences.

As the number of listeners increases, they collectively influence the music recommendations. However, the broadcaster can always override recommendations.

Service Design: Scalability


ROADCASTING Service Design: Scalability


ROADCASTINGOverview


Scope

Scalability


Search vs. Browse

XM Expert Analysis


Future Plans

Agenda


ROADCASTING

In-vehicle systems must not demand a driver’s attention in order to function.

We designed the broadcasting and listening interactions to afford a variety of attention levels. The system will even function without any user input.

Design Rationale: Lightweight Interaction

Managed Guided Unmanaged

Active Passive

Broadcaster

Listener


ROADCASTING

Search vs Browse

Technical limitations led to our decision to incorporate browsing rather than searching in the interface.

BUT, for future iterations, what are the implications of both searching and browsing with respect to Roadcasting?

We performed a literature review to answer that question.

Design Rationale: Search vs. Browse


ROADCASTING

Literature review findings and implications

FindingWhen browsing, people care more about navigation and information organization. When searching, product details are more important.

Design implication For browsing: efficient navigation and organization of the categories and stations is essential.

For searching: users should be presented with detailed information in order to ensure that the correct song/station was found.



ROADCASTINGFindingSearch rate for specific items was greater than search rate for general items, but not statistically significant.

Design implicationBrowsing for a specific song or station might be just as preferable as searching.

FindingBrowse function had higher success rate than search function, though not statistically significant. Failure rates were even.

Design implication Users may be more likely to find the song/station that they are looking for by using menus.



ROADCASTING

FindingSuccessful product locations took more time than unsuccessful attempts, whether searching or browsing.

Design implication Success is more difficult to judge than failure.



ROADCASTINGMusic domain conclusions

FindingCD store shoppers alternate between search and browse as there are advantages to both modes.

Design implication Building a system that allows seamless switching between searching and browsing would be most appropriate.

FindingThe ability to listen to song clips would then support a natural way for users to verify they have selected the right song.

Design implicationWhen listeners vote, instead of just showing the song title and artist name, also play a short (5 sec) sound clip.



ROADCASTING

FindingMusic shopping and selection is surprisingly visual.

Design implication

Possibly an album of the song that's currently playing?



ROADCASTING

Problem with XMEach station is identified by both a number of a unique name, forcing the user to memorize which station is associated with which number.

Design solutionSince we are not implementing a search function, stations can be identified by either name or number, not both. This is more appropriate for non-persistent stations.

Problem with XMCurrent song title playing is truncated if it is too long instead of using entire display.

Design solutionMake efficient use of screen real estate. This will give users more detailed information about the stations.

Design Rationale: XM Expert Analysis

Problem with XMIt isn’t clear how to set presets or how to access them.

Design solutionEliminate presets. This is possible since system is already knowledgeable of user’s music tastes

Problem with XMVisual attention to the display is required while scrolling through stations.

Design solutionAllow scanning through stations so that users can hear each song being played as they scroll to find a station they like. This will make navigation more natural and spontaneous.


ROADCASTING

Problem with XMCategories are not organized in a meaningful way

Design solutionOrganize categories according to user preference. This will reduce the amount of scrolling a user will need to do in order to find a category she enjoys.

Problem with XMStations are organized by channel number, and in no understandable order.

Design solutionOrganize stations according to user preference. This will reduce the amount of scrolling a user will need to do in order to find a station she enjoys.


Problem with XMStations sometimes play a strange order of songs: Paul McCartney -> Kiss -> Joe Cocker.

Design solutionSystem should suggest next song to Broadcaster that has a similar tempo to what is being played. This will keep the tone of the station somewhat steady.

Problem with XMStations play the same artists repeatedly.

Design solutionIn Unmanaged and Guided modes, system should suggest songs and artists that haven’t recently been played.


ROADCASTING

Good aspect of XMStations play rare versions of songs that most listeners haven’t heard.

Design implementationLook for alternate versions of Listeners’ owned songs on Broadcaster’s playlist – remixes, covers, live versions, etc…

Good aspect of XMStations use celebrities, sound collages, and DJs to strengthen station identity.

Design implementationProvide opportunities for Broadcaster to automatically or manually play a recording of her station identification.



ROADCASTINGOverview


Scope

Scalability


Search vs. Browse

XM Expert Analysis


Future Plans

Agenda


ROADCASTINGPrototype architecture



ROADCASTING Implementation Details

Collaborative filteringListener preferences are created based on the listener’s MP3s or iTunes library data.

The listener’s preferences are sent to the broadcaster when the listener tunes in to a station.

(For now) a simple Pearson correlation is calculated from all audience preferences, and determines which songs, artists and genres are most preferred by the listening audience.



Station flavor

A broadcaster can set restrictions regarding the type of music his station plays. This ‘station flavor’ determines what songs the broadcaster has that can be played.

This station flavor is also broadcast as part of a station’s identity, so a listener’s tuner can know which stations she is likely to prefer based on her preferences.



Audio rendering

Songs are pulled from the station playlist and sent to listeners.

MP3 files (or live voice from the broadcaster) are multicast to the audience using the Java Realtime Streaming Protocol.



Polling

A listener can press her voting buttons at any time. These votes are visible to the broadcaster, so allowing him to conduct polls on-air and see live results from his audience.


ROADCASTINGOverview


Scope

Scalability


Search vs. Browse

XM Expert Analysis


Future Plans

Agenda


ROADCASTING Future Plans: Timeline


ROADCASTING Future Plans: Next Steps

Continue to address low-level design issues

Two-member teams:

Jordan and Whitney will look into the specifics of how voting will work and how Broadcasters will talk over their music or between songs.

Should Broadcasters hit an “On-Air” button to broadcast their voice?

How do they propose a vote on music content?

Can they pose a question on non-music content (i.e., trivia)?

Megan and Mathilde will look into interruption issues for Broadcasters and Listeners

Should Listeners be notified of new stations as they enter the network?

Should Listeners see a timeline indicating remaining/elapsed time of a current song?

How will Broadcasters and Listeners be notified to make a vote?

How will Listeners switch between Active and Passive modes?


ROADCASTING Future Plans: Next Steps

Issues to be tackled by the entire group

Should the Broadcaster know how many people are listening to his station?

Should the Listener see station stats (i.e., signal strength, location, popularity/reputation)?

How are stations uniquely identified?

How do Broadcasters set the flavor/format of their station?


ROADCASTING Questions

Questions?

CMU MHCI - GM Network Project19 May 2004 ROADCASTING GM Car Network Project Jim Garretson Whitney...

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