論文 - 山本　晶

Optimal Heterophily for Word-of-Mouth Diffusion

Yamamoto, Hikaru, and Matsumura, Naohiro

Proc. International Conference on Weblogs and Social Media (ICWSM2009)    350 - 353 2009年05月

研究論文（学術雑誌）, 単著, 査読有り

Community Gravity: Measuring Bidirectional Effects by Trust and Rating on Online Social Networks

Matsuo, Yutaka and Yamamoto, Hikaru

Proc. 18th International World Wide Web Conference (WWW2009)    751 - 760 2009年04月

研究論文（国際会議プロシーディングス）, 共著, 査読有り

　概要を見る

<p>Several attempts have been made to analyze customer behavior on online E-commerce sites. Some studies particularly emphasize the social networks of customers. Users' reviews and ratings of a product exert effects on other consumers' purchasing behavior. Whether a user refers to other users' ratings depends on the trust accorded by a user to the reviewer. On the other hand, the trust that is felt by a user for another user correlates with the similarity of two users'ratings. This bidirectional interaction that involves trust and rating is an important aspect of understanding consumer behavior in online communities because it suggests clustering of similar users and the evolution of strong communities. This paper presents a theoretical model along with analyses of an actual online E-commerce site. We analyzed a large community site in Japan: @cosme. The noteworthy characteristics of @cosme are that users can bookmark their trusted users; in addition, they can post their own ratings of products, which facilitates our analyses of the ratings' bidirectional effects on trust and ratings. We describe an overview of the data in @cosme, analyses of effects from trust to rating and vice versa, and our proposition of a measure of of community gravity, which measures how strongly a user might be attracted to a community. Our study is based on the @cosme dataset in addition to the Epinions dataset. It elucidates important insights and proposes a potentially important measure for mining online social networks. Copyright is held by the International World Wide Web Conference Committee (IW3C2).</p>

• Access to Document (DOI)

The Power of Grassroots Influentials

Yamamoto, Hikaru, and Matsumura, Naohiro

Proc. International Symposium on Social Intelligence and Networking (SIN-09) 4   456 - 462 2009年

研究論文（国際会議プロシーディングス）, 共著, 査読有り

　概要を見る

<p>Previous research on word-of-mouth (WOM) diffusion has focused on the attributes of the sender, such as opinion leadership and innovativeness. This paper focuses on the social relationship between WOM senders and receivers and attempts to identify the optimal heterophily for WOM diffusion. The results of empirical analysis using both offline survey data and online blogosphere data provide evidence of optimal heterophily between the two; i.e., the WOM receiver wants to receive information from someone slightly more knowledgeable, not from a distant expert. The context of WOM communication is also examined in terms of the stage of hierarchical consumer behavior and sentiment. Finally, the patterns of influence are presented to depict the diffusion process. This analysis of optimal heterophily and the patterns of influence suggest that many grassroots influentials, rather than a few super influentials, play a central role in WOM diffusion.</p>

• Access to Document (DOI)

インターネットと消費者間相互作用

山本 晶

東京大学学位論文 2008年02月

単著, 査読有り

クチコミのキーパーソンとその発見方法

山本晶

季刊マーケティングジャーナル 27 （ 3 ） 125 - 131 2008年01月

単著

Finding Influencers and Consumer Insights in the Blogosphere

Matsumura, Naohiro, Yamamoto, Hikaru, and Tomozawa, Daisuke

Proc. International Conference on Weblogs and Social Media (ICWSM2008)    76 - 83 2008年

研究論文（国際会議プロシーディングス）, 共著, 査読有り

　概要を見る

<p>In this paper, we attempt to specify the influencer and the influential terms in consumer package goods by using the influence diffusion model (IDM). IDM calculates the spread of a term in the blogosphere recursively, and evaluates the influence of terms, blog entries, and bloggers. The model was applied to the official data from a blog hosting service. The results of the model were compared with the term frequency (TF). Then, the influencers of the IDM were examined and compared with the results of other network indices such as number of links and trackbacks. The results indicate that IDM performs better in finding blogs posted by bloggers with product usage experience or with an interest in the product. A propagation network which visualizes the consumer-oriented key marketing elements is also presented. An empirical analysis suggests the validity of IDM for marketing decision marking.</p>

インフルエンサーの発見とクチコミの効果～AIDEESモデルの実証分析～

山本 晶・片平秀貴

季刊マーケティングジャーナル （日本マーケティング協会）  28 （ 1 ） 4 - 18 2008年

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0389-7265

テーマ書評(62)クチコミのキーパーソンとその発見方法

山本 晶

マ-ケティングジャ-ナル （日本マーケティング協会）  27 （ 3 ） 125 - 131 2008年

研究論文（学術雑誌）, 単著, 査読有り,  ISSN  03897265

Diffusion of Recommendation through a Trust Network

Matsuo, Yutaka and Yamamoto, Hikaru

Proc. International Conference on Weblogs and Social Media (ICWSM2007)    287 - 288 2007年03月

研究論文（国際会議プロシーディングス）, 共著, 査読有り

　概要を見る

<p>Several attempts have been made to analyze information diffusion on online knowledge sharing sites. In this poster, we report a preliminary study analyzing @cosme, a viral marketing site, which is among the largest community sites in Japan. The notable characteristics of @cosme are that users can bookmark their favorite reviewers; moreover, they can post their own reviews of products. In other words, a user puts trust in some other users for their reviews. This trust relation affects the opinions of users: A user refers to the ratings and opinions from the user's own favorite users when purchasing products; some users come to be trusted by a user based on mutual similarities of ratings and opinions. This bidirectional interaction between trust and opinion is an important phenomenon that elucidates consumer behaviors in online communities. In this paper, we describe an overview of the data in @cosme, analyses of recommendation through the trust relation, and concept for future analyses.</p>

インターネット時代の新しい消費者行動モデル

山本晶

三色旗 707   15 - 19 2007年02月

研究論文（学術雑誌）, 単著, 査読有り

Generating social network features for link-based classification

Karamon Jun, Matsuo Yutaka, Yamamoto Hikaru, Ishizuka Mitsuru

  127 - 139 2007年

研究論文（国際会議プロシーディングス）, 共著

　概要を見る

<p>There have been numerous attempts at the aggregation of attributes for relational data mining. Recently, an increasing number of studies have been undertaken to process social network data, partly because of the fact that so much social network data has become available. Among the various tasks in link mining, a popular task is link-based classification, by which samples are classified using the relations or links that are present among them. On the other hand, we sometimes employ traditional analytical methods in the field of social network analysis using e.g., centrality measures, structural holes, and network clustering. Through this study, we seek to bridge the gap between the aggregated features from the network data and traditional indices used in social network analysis. The notable feature of our algorithm is the ability to invent several indices that are well studied in sociology. We first define general operators that are applicable to an adjacent network. Then the combinations of the operators generate new features, some of which correspond to traditional indices, and others which are considered to be new. We apply our method for classification to two different datasets, thereby demonstrating the effectiveness of our approach.</p>

顧客間インタラクションがサイト・ロイヤルティに与える影響-インターネット視聴率データの分析-

山本 晶

消費者行動研究 12 （ 1,2 ） 23 - 36 2006年

研究論文（学術雑誌）, 単著, 査読有り

発信する顧客は優良顧客か？-サイトの訪問動機とオンライン・ショップの購買履歴データの分析-

山本 晶

消費者行動研究 11 （ 1,2 ） 35 - 49 2005年

研究論文（学術雑誌）, 単著, 査読有り

発信する顧客は優良顧客か?

山本 晶

消費者行動研究 （日本消費者行動研究学会）  11 （ 1 ） 35 - 49 2005年

研究論文（学術雑誌）, 単著, 査読有り,  ISSN  1346-9851

• Access to Document (DOI)

企業サイトが消費者態度に与える影響―オンライン経験とオフライン経験の相互作用

山本 晶

マーケティング・サイエンス 11((1)(2)) 60-74 2003年 11 （ 1,2 ） 60 - 74 2003年

研究論文（学術雑誌）, 単著, 査読有り

Net or die: 新しい消費者が迫る新しい企業モデル

片平秀貴・山本 晶

一橋ビジネスレビュー 50(3) 74-89 2002年 （東洋経済新報社）  50 （ 3 ） 74 - 89 2002年

研究論文（学術雑誌）, 共著,  ISSN  1345-9953

平成13年度若手論文セッション研究奨励賞受賞論文 企業サイトが消費者態度に与える影響--オンライン経験とオフライン経験の相互作用

山本 晶

マーケティングサイエンス （日本マーケティング・サイエンス学会）  11 （ 1 ） 60 - 74 2002年

研究論文（学術雑誌）, 単著, 査読有り