In recent years, fandoms have expanded beyond national and regional boundaries thanks to the proliferation of social media. Social movements based on such connections are attracting attention because of fan activism. However, such fan activities also need to be carefully analyzed. While studying the autonomy and enjoyment of fan activism, Fandom Studies has criticized the possibility of fans being exploited by the cultural industry and mass media. This study is a case analysis based on Fandom Studies of the fan activities of K-pop fans using social media today. During the period when K-pop idols were unable to perform in Japan due to the covid-19 disaster, online interactive communication products were sold between the idols staying in South Korea and their fans living in Japan. The qualitative findings of this study revealed that while Japanese female fans enjoyed these online products, they tended not to continue purchasing them if they did not like them. By contrast, fans in the U.S. and Southeast Asia are enthusiastic about social movements aimed at elevating the K-pop image and solving social issues important to them. South Korean entertainment companies are also enthusiastic about social movements because efforts to resolve social issues are necessary for success in American show business. Japanese female fans were active in protecting K-pop idols, who were forced by their foreign fans to donate money and publicly endorse groups associated with social issues. The above attitude of valuing their own enjoyment and kindness to others probably serves an autonomous function in their fan behavior. It can be concluded that the above sensitive considerations are important in situations where people living in different everyday worlds use smartphones to enjoy and encounter diverse entertainment content.

本稿では，電子メールやチャットによって質問を受け付けるヴァーチャルレファレンスサービスについて，2020年以降に国際図書館連盟やアメリカ図書館協会，ラトガース大学の研究者および図書館員が実施した合計6つの調査から，コロナ禍における海外の動向について報告した。各調査の結果からヴァーチャルレファレンスサービスに関する内容を抜粋し整理したところ，ヴァーチャルレファレンスサービスの導入状況や受付方法の多様さ，質問件数が増加傾向にあること，また，大学図書館のチャットレファレンスにおいては質問内容の変化についても明らかになった。

デジタルレファレンスの分野では図書館に限らず関連する情報機関がさまざまなサービスを提供している。その中から米国におけるいくつかの事例を視察しその動向を調査した。その結果，デジタルレファレンスサービスは図書館において現実に定着し着実に進展していることが確認できた。今後ネットワーク環境下で電子図書館サービスが進展するにつれてデジタルレファレンスの重要性が高くなることが予測される。

製薬企業のコールセンターには，薬についての問い合わせが多く寄せられる．その内容は多岐に渡ることから，新製品発売準備に経験値がない場合は対応の困難が想定される．本研究では，発売初期の製品の問い合わせ内容の汎用性に着目し，発売初期の製品問い合わせ内容を入力データとして，テキスト分析することにより，問い合わせ内容の種類を概念として抽出し，構造化し，可視化した．さらに，抽出した概念を用いて同じ製品の期間別のデータと，疾患領域が異なる別製品のデータに対して適用し，汎用性を検証した．その結果，発売初期の製品から抽出した概念は，発売初期以降の期間と疾患領域が異なる製品においても包括的に適用可能であることが確認された．抽出した概念には期間によって増加傾向や減少傾向の特徴を示すものがあり，異なる2製品に増減傾向の共通性と特異性が確認された．このことから，新製品発売準備における実務的な示唆を得られた．

 Scholars in the fields of management and economics note the importance of gaining users and achieving network effects in online C2C platforms (OCP). Although the extant literature stresses the importance of network effects and the “quantity” of users, another important factor in OCP—the “quality” of users—is often ignored. Poor quality users harm the platform's reputation; their presence makes potential users hesitant to join it. Thus, we thus build a framework for managing users' quality in OCP, and, then, analyze how managing users' quality affects trust in C2C platforms and the transaction intention of users.

 We build a framework for analyzing users' quality with two pairs of influential factors: ex-ante and ex-post, and top and bottom users. These two pairs lead to four quadrants. Quadrant 1 has ex-ante and bottom users; it signifies platform firms' behavior to restrict bad users from joining by ex-ante screening (entrance fees or some qualifications). Quadrant 2, which is ex-ante and top, signifies how platform firms attract superstars. Quadrant 3 is ex-post and top and signifies how platform firms educate and finally convert normal users to loyal ones. Quadrant 4—ex-post and bottom users—signifies how platform firms find users that satisfy their criteria; this helps to exclude the bad users already present on the platform.

 To analyze this framework, the present study analyzes data obtained from OCP users of Mercari and Airbnb by distributing 461 questionnaires (Mercari n=242, Airbnb n=219) through a research company.

 We find that: (1) controlling bottom users (limited participation) increases trust in C2C platforms, and (2) controlling top users (favorable treatment for high quality users) increases the transaction intention of users. This paper highlights the issue of users' quality in OCP by building a framework for managing it—something prior research neglected by focusing on network effects.