MusicFX:MusicFX:An Arbiter of Group Preferences for An Arbiter of Group Preferences for

Computer Supported Collaborative WorkoutsComputer Supported Collaborative Workouts

Joe McCarthyJoe McCarthy Ted AnagnostTed Anagnost

Andersen ConsultingAndersen Consulting

Center for Strategic Technology ResearchCenter for Strategic Technology Research

OutlineOutline

• UbiComp & Intelligent EnvironmentsUbiComp & Intelligent Environments

• The MusicFX SystemThe MusicFX System

• Evaluating Group Preference ArbitrationEvaluating Group Preference Arbitration

• Future WorkFuture Work

Ubiquitous ComputingUbiquitous Computing• Proliferation of networked devicesProliferation of networked devices

– phones, TVs, cam's, mic's, microwaves, refrigerators...phones, TVs, cam's, mic's, microwaves, refrigerators...

• Distribution of computing resourcesDistribution of computing resources– portable, wearable, embeddedportable, wearable, embedded

• New paradigm of computingNew paradigm of computing– input/output (input/output (foregroundforeground) --> ) -->

sense/respond (sense/respond (backgroundbackground))

Intelligent EnvironmentsIntelligent Environments

• ““UbiComp in a box”UbiComp in a box”– Interconnected, cooperating devicesInterconnected, cooperating devices– Concentrated in a small area (e.g., one room)Concentrated in a small area (e.g., one room)

• Redefining HCIRedefining HCI– users --> users --> inhabitantsinhabitants

Observation 1Observation 1• Most UbiComp applications focus onMost UbiComp applications focus on

single individualssingle individuals in in multiple spacesmultiple spaces– Active Badge: open doors, teleportingActive Badge: open doors, teleporting– ParcTab: information access, emailParcTab: information access, email

• What about What about multiple inhabitantsmultiple inhabitants in a in asingle, shared spacesingle, shared space??

Observation 2Observation 2

Music in the Fitness Center (FX)Music in the Fitness Center (FX)• Popular in the Complaint DepartmentPopular in the Complaint Department

– 25% of “feedback” focused on music25% of “feedback” focused on music

• RSI: Repetitive Song Injury RSI: Repetitive Song Injury – 3 stations played, 91 available (DMX)3 stations played, 91 available (DMX)

• Squeaky WheelsSqueaky Wheels– Vocal minority prevails over silent majorityVocal minority prevails over silent majority

• HangoversHangovers– This morning’s music = last night’s musicThis morning’s music = last night’s music

Four Issues for anyFour Issues for anyIntelligent EnvironmentIntelligent Environment• Who’s here?Who’s here?

• What are they doing?What are they doing?

• What are their preferences?What are their preferences?

• What can I do to help?What can I do to help?

Four Issues for MusicFXFour Issues for MusicFX• Who’s here?Who’s here?

– Members who login [badge reader]Members who login [badge reader]

• What are they doing?What are they doing?– Working out while listening to musicWorking out while listening to music

• What are their preferences?What are their preferences?– Diverse (to say the least)Diverse (to say the least)

• What can I do to help?What can I do to help?– Play “good” musicPlay “good” music

The MusicFX SystemThe MusicFX System

• Database of musical preferencesDatabase of musical preferences

• Group Preference Arbitration algorithmGroup Preference Arbitration algorithm– Group Preference CalculationGroup Preference Calculation– Candidate IdentificationCandidate Identification– Weighted Random Selection operatorWeighted Random Selection operator

Music Preference DatabaseMusic Preference Database• 275 fitness center members275 fitness center members• 91 musical genres (DMX stations)91 musical genres (DMX stations)• 5-point rating scale5-point rating scale

  +2+2 = I = I lovelove this music this music  +1+1 = I = I likelike this music this music  00 = I = I don’t minddon’t mind this music this music  -1-1 = I = I dislikedislike this music this music  -2-2 = I = I hatehate this music this music

Group Preference ArbitrationGroup Preference Arbitration

• Group Preference CalculationGroup Preference Calculation

• Candidate IdentificationCandidate Identification

• Weighted Random Selection Weighted Random Selection

Group Preference CalculationGroup Preference Calculation

N

jjii IPGP

1

2, 2

WhereWhere•GPGPii = = GGroup roup PPreference for genre reference for genre ii•IPIPi,ji,j = = IIndividual ndividual PPreference of person reference of person jj for genre for genre ii•NN = = NNumber of inhabitantsumber of inhabitants

Candidate IdentificationCandidate Identification

• Sort genre list by Sort genre list by GPGPii

• Remove any undesireable genre Remove any undesireable genre – Individual Preference FilterIndividual Preference Filter

• Candidates are the first M genreCandidates are the first M genre– Group Preference FilterGroup Preference Filter

Weighted Random SelectionWeighted Random Selection

• Calculate weights for candidatesCalculate weights for candidates

• Probabilistically select genre according to Probabilistically select genre according to WWii

M

iiGPTW

1 TW

GPW i

i

An exampleAn examplei Genre Person A B C D E GP i Pr i

1 Alternative Rock 2 2 0 2 2 68 0.48

2 Hottest Hits 1 1 2 0 -2 38 0.27

3 New Music 1 1 1 0 0 35 0.25

4 Hot Country 2 0 0 0 -2 28 0.00

5 Dance 2 -1 1 -1 -1 28 0.00

6 World Beat 0 1 -1 1 -2 23 0.00

7 Traditional Country 1 0 0 -2 -2 17 0.00

8 50's Oldies 0 0 0 -1 -1 14 0.00

9 Heavy Metal -1 -1 -1 -1 -2 4 0.00

10 Polka -1 -1 -2 -2 -2 2 0.00

Environmental EventsEnvironmental Events• Member entranceMember entrance

– Login (badge reader)Login (badge reader)

• Member exitMember exit– Timeout (90 minutes)Timeout (90 minutes)

• Individual Preference UpdateIndividual Preference Update• System Parameter AdjustmentSystem Parameter Adjustment

– Individual / Group Preference Filter, Maximum Play TimeIndividual / Group Preference Filter, Maximum Play Time

• Maximum Play Time ElapsedMaximum Play Time Elapsed

The Success of MusicFX The Success of MusicFX • Daily operation since November 1997Daily operation since November 1997• Poll results (after 6 weeks)Poll results (after 6 weeks)

: increased variety, : increased variety, having some influence having some influence

: abrupt changes, : abrupt changes, occasional “bad” music occasional “bad” music

Better71%

Same8%

Worse7%

N/A14%

Evaluating Evaluating Group Preference ArbitrationGroup Preference Arbitration

• Calculate the “goodness” of MusicFXCalculate the “goodness” of MusicFX

• Estimate the “goodness” of old schemeEstimate the “goodness” of old scheme

• Compare the old with the newCompare the old with the new

The “Goodness” of MusicFXThe “Goodness” of MusicFX

  Individual Satisfaction rating (Individual Satisfaction rating (ISIS))– TimeTimei,ji,j = time person = time person jj spent listening to genre spent listening to genre ii

– IPIPi,ji,j = person = person jj’s Individual Preference for genre ’s Individual Preference for genre ii

1

,

,, *i

n ji

jijij Time

IPTimeIS

The “Goodness” of MusicFXThe “Goodness” of MusicFX

  Overall Satisfaction rating (Overall Satisfaction rating (OSOS))– For all For all NN members members

N

ISOS

j

Nj

1

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

IndividualIndividualSatisfactionSatisfactionfor all 275for all 275FX MembersFX Members

The “Goodness” of the Old DaysThe “Goodness” of the Old Days• Three genres (Three genres (n=3n=3))

– Hottest Hits, Power Hits, DanceHottest Hits, Power Hits, Dance– Assume each person listened to each genre 1/3 Assume each person listened to each genre 1/3

of the total time spent working outof the total time spent working out

1

3

,

3

*ijij

j

IPTotalTimeIS

Comparing the Old with the NewComparing the Old with the New

  Overall SatisfactionOverall Satisfaction– ““Old scheme”: Old scheme”: 0.440.44– MusicFX: MusicFX: 0.640.64

• 8% higher (statistically significant)8% higher (statistically significant)

Average Individual PreferencesAverage Individual Preferences

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

Top 10 StationsTop 10 StationsStation

Percent of Total Airtime

Alternative Rock 14.3Album Rock 9.0Power Hits 8.6

Classic Rock 7.9Hit Sweep 7.780's Music 7.6Hottest Hits 7.5

Dance 6.5

New Music 4.4Adult Contemporary 3.6

MusicFX AnecdotesMusicFX Anecdotes

• Veto power & IPFVeto power & IPF

• Uncommon varietyUncommon variety

• The Polka incidentThe Polka incident

• The Chinese Music incidentThe Chinese Music incident

The Future of MusicFXThe Future of MusicFX

• Better awareness of inhabitantsBetter awareness of inhabitants

• Alternative rating/voting schemesAlternative rating/voting schemes

• Alternative arbitration schemesAlternative arbitration schemes

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

IndividualIndividualSatisfactionSatisfaction

after 6 monthsafter 6 months(Avg: 0.64)(Avg: 0.64)

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

AverageAveragePreferencesPreferences

after 6 monthsafter 6 months(Avg: -0.39 (Avg: -0.39 to -0.50) to -0.50)

Future Group Preference ApplicationsFuture Group Preference Applications