Network Analysis of Massively
Collaborative Creation ofMultimedia Contents
Case Study of Hatsune Miku videos
on Nico Nico Douga
Masahiro Hamasaki,,Hideaki Takeda, Takuichi Nishimura(1) National Institute of AIST, Japan(2) Japan Science and Technology Agency, CREST(3) National Institute of Informatics (NII)

Massively Collaborative Creation• A new style for content creation enabled by Web– Web 2.0 styley on content creation• Key features– Massive
M i participationi i i• Numerous people are involved, even though they often donot knowkeachh otherh– Creating contents collaboratively• Contents are created as a result of many people’ effort• Just sharing contents is not enough. Collaboration isimportant

Massively Collaborative Creation• Examples (text content)– Wikipedia:pYes– Yahoo! Q and A: Yes–…

• Examples (multimedia content)– YouTube: No in general (few collaborative creation)– “Hatsune
Hatsune Miku
Miku” phenomena on Nico Nico Douga:
Yes!

“Hatsune
Hatsune Miku
Miku” Phenomena• A lotl off video
id related
l d to “Hatsune“Miku”
ik ” areposted to a video site (“Nico Nico douga”)• It’s really Massively Collaborative Creation ofMultimedia contents– Massive Participation: Yes• Thousands of people create tens of thousands of videos– Collaborative Creation: Really Yes!
• Sharing and Re‐using of digital contents– Multimedia:
M l i di Really
R ll Yes!
Y !
• Sounds (songs and music), pictures (2D & 3D), movies

Example!!

• Title: Shooting star –short ver.‐ like an ending movie• Creator: ussy
• URL: http://www.nicovideo.jp/watch/sm2030388

Re‐using on
Nico Nico Douga & Hatsune MikuPicture
Many pictures by many authors
SongShooting star
Creator: minato

Song andMovie3D model

Shooting star–complete ver.‐
Creator: FEDisMovie

Shooting star –short ver.‐like an ending movie
Creator: ussy
3D model3D Miku sings ‘01_ballede’Creator: kiokio

Songmelody… 3D PV ver1.50
Creator: ussy

melody…
Creator: mikuru396

A part of network of re‐using relationship among
creators using Hatune Miku on Nico Nico DougaFindings• Massively collaboration creation generates
g and sparsepconnected creators’ networklarge• Different categories of creators have different
roles in evolving the network• Creators’ behavior is similar to audiences’ one– It likes Web2.0 style (A consumer is a creator!)• Some of communities in the network arecentralized, and others aren’tOur Approach• We adopted a method of social networky as a basic method to investigategtheanalysis
phenomenon• We investigate how different types of creatorsinteract to create new content through theirsocial network

Nico Nico Douga & Hatsune Miku
• Ni
Nico Nico
Ni Douga
Di thisthemost popular video
sharing website in Japan– The most interesting
function is the direct
overlaying of commentson videos• Hatsune Miku is aversion of singing
synthesizer application
software– It has inspired many
people to produce
variousimusic,
i picture,i t
and video compositions

Data Collection• 36,709
36 709 videos
idwithi h tag ’Hatsune’H
Mik ’ (31 May 2008)
Miku’• Select 7,138 videos viewed more than 3,000 times– Crawled during 1–5 June 2008
– The metadata include view times, uploaded date, uploader
name, tags, and a description• 7,138 videos were uploaded by 2,911 unique contributors– Note:Note• We regard the uploader as the video creator• On Nico Nico Douga,g , onlyy the uploader
pis identified• The uploader may not be the creator of the vide

How to make video’s
video s network• The description of the movie often includes hyperlinks toother videos showing trail of the video’s creation– On Nico Nico Douga, a creator cites other videos if a sound, image,or any part of another video is used as acknowledgement• By tracing these hyperlinks,
hyperlinks we generated a reference
network of videos• Among the collected videos, 4,585 videos include hyperlinks
in the description• Movie network– 4,585,nodes (videos)()– 12,507 links (hyperlinks among videos)Videos’ network
nodes:
d 4,585
edges: 12,507

How to make creator’screator s network• We
W set a relationl i fromf
creator off video
id A to creator offvideo B if video A has link to video B
It implies that Creator A uses contents of Creator B• In this way, we generated a network among creators• Creators network– 2,164
2 164 nodes (creators)– 4,368 links (relationships among creators)• We regard this network as a social network of creators

Creators network
Creators’nodes: 1,362
g 2,270,
edges:
Red: Songwriting
Blue: Song creation
Green: Illustration

Characteristics of the Network• Theh networkk iis llarge andd sparse– The diameter of this network is 21• ScaScalee freeee network
et o– A few nodes (creators) gather many links (citation)• Network centrality correlated to the number ofplay times– Many cited videos are popular for users– Creators’
C t ’bbehavior
h i isi similari il tot audiences’di’ oneCategory of Creation Activity• We classified
l ifi d creativei activities
i i i related
l d toHatsune Miku into four categories:– Songwriting• Create an original song (lyrics and melody)– Song creation• Tune the software to create singing songs– Illustration• Drawing their favorite characters by themselves• Produce many different scenes and facial expressions– Editing• Choice videos and package them to one video

Classify videos• ClClassify
if videosidandd creatorst iintot creation
ti categories
tiautomatically using tags for videos• Provide a set of tags that are important for specific creation
categories.
– Ex.
E Tag
T “Miku“Mik Original
O i i l SSong”” ‐> Category
C t“Songwriting”“Siti ”– Ex. Tag “3D Hatsune Miku Project” ‐> Category “Illustration”• A video is classifiable into two or three categories if it has
tags for these categories• The creator’s category is generated by aggregating her/his/works• Furthermore, we manually excluded 179 Editing videos

Relationship among
categories of creation
58

20370

I(Illustration)

C(Song creation)

13159I&CW(Songwriting )

75

W&I

241

68

102

65

200

149

58

W&C

149

unknown

53
W&I&C

152

Community on Creators Network• WeW analyzel
theth creators’t ’ communityit– The term ”creators’ community” means a tight groupof nodes within social network of creators– We adopt Newman clustering to detect such
communities from the social network of creators• Newman clusteringg generated
g83 clusters(communities) from the social network ofcreators• We especially investigated 10 clusters of which
the size is greater than 50

Structure of the biggest clusters• Songwriting is often a key person, meaning
gg triggers
gg creative activityythat Songwriting#12345678910Size
161
144
118
95
91
90
79
56
55
51

Type
centeredmessycenteredmessycentered
centered
centeredmessycenteredmessy

Key person
W
I&C
I
W&C
W
W&C
-Majority
III, CI
IC
C
C,C&I
C
I

W: SongWriting, C: Song Creation, I: Illustration

Cluster 1• Type– Centered• Key person– Songwritinggg• Majority– Illustration

Cluster 2• Type– Messy• Majority– Illustration

Cluster 3• Type– CenteredThe center of this cluster introduced a character called``Hachune Miku'' (an infantilized version of the Hatsune
Miku mascot) with leak

• Key person– Illustration &Song creation• Majority
j y– Illustration ,Song creation

Cluster 4• Type– Messy• Majority– Illustration

Cluster 5• Type– Centered• Key person– Illustration• Majority– Illustration

Cluster 6• Type– Centered• Key person– Songwritinggg&Illustration• Majority
j y– Song creation

Cluster 7• Type– Centered• Key person– Songwritinggg• Majority– Song creationConclusion• WeW have
hinvestigated
iti t d how
h different
difft typestoffcreators interacted in massively collaborative
creation• We extracted and analyzed the social networks ofcreators revealing some interesting facts
creators,– Creator’s network is large and sparse– Different categories
gof creators have different roles inevolving the network– Creators’ behavior is similar to audiences’ one– Some of communities in the network are centralized,
and some aren’tCreation Activity: Songwriting• Using Vocaloid, users can produce sound withpmusic
vocalizations as computer– It inspires amateur songwriters to publish their
original songs with Hatsune Miku
Songwriting

Songwriting

Songwriting

Title: Vocaloid in love
Creator: Fuwa Fuwa Cinnamon

Title: Mikku miku
Creator: ika

Title: melody…
Creator: mikuru396

Creation Activity: Song Creation• Certain techniques are necessary to tune
HatsuneMiku, but it is fun to tune the software tocreate nice singing songs
Illustration

Song creation

re‐using
originalsong

re‐using
movie
Title: Make It Sing
“Make It Dance ‘Valalaika’”
Creator: Soba allergy

Title: Make It Dance‘Valalaika’
Creator: Asami

Valalaika(Professionalartist’s song)

Aasami creates the video without songs, then Soba allergy tune and new video with the song

Creation Activity: Illustration• The image of Hatsune Miku is a typical anime
character and attracts anime fans
Illustration

Songwriting

re‐using
originalsong
Title: melody… 3D PV
ver1.50
Creator: ussy

Title: melody…
Creator: mikuru396

ussy creates the video for the original song ‘melody…’ created by mikuru396

Creation Activity: Editing• There are so many Hatsune Miku videos thatpeoplep collect them and producepsome psummary videos, with ranking programs ofHatsune Miku videos
Editing

Choice 38 songs
Title: Best choice!
Hatsune Miku Medley
Creator: LarK