The success or failure of social media is highly dependent on the active participation of its users. In order to examine the influential factors that inspire dynamic and eager participation, this study investigates what motivates social media users to share their personal experiences, information, and social support with anonymous others. A variety of information-sharing activities in social media, including creating postings, photos, and videos in 5 different types of social media: Facebook, Twitter, Delicious, YouTube, and Flickr, were observed. Ten factors: enjoyment, self-efficacy, learning, personal gain, altruism, empathy, social engagement, community interest, reciprocity, and reputation, were tested to identify the motivations of social media users based on reviews of major motivation theories and models. Findings from this study indicate that all of the 10 motivations are influential in encouraging users' information sharing to some degree and strongly correlate with one another. At the same time, motivations differ across the 5 types of social media, given that they deliver different information content and serve different purposes. Understanding such differences in motivations could benefit social media developers and those organizations or institutes that would like to use social media to facilitate communication among their community members; appropriate types of social media could be chosen that would fit their own purposes and they could develop strategies that would encourage their members to contribute to their communities through social media. IntroductionMotivation is one of the essential factors that encourage people to carry out actions in everyday life. In education, motivation strategies for students' active learning have been developed and examined (Newby, 1991). In business, the relationships between employees' motivations and their quality of work have been investigated to create positive attitudes and efficiency in corporations (Herzberg, Mausner, & Snyderman, 1993). The ways to motivate consumers to buy goods or services have been examined (Tuten & August, 1998). Motivations also have been studied in clinical settings to encourage patients to manage physical and mental health problems, such as heavy smoking, alcohol or drug addiction, diabetes, eating disorders, anxiety, and depression (Sheldon, Williams, & Joiner, 2003).In information science, research on motivation has mostly been carried out in order to understand people's behaviors when seeking information. Motivation is an affective factor that enables people to initiate, continue, and terminate information seeking (Nahl, 2001(Nahl, , 2004). One's motivation can increase or decrease depending on to what degree the person is cognitively or affectively stimulated by the search process and results. The motivational factors in information seeking have been tested with various groups, such as middle and high school students (Heinström, 2006), the Y generation (Weiler, 2004), college students (Small, Zakaria, & El-Figuigui, 2004), focus...

Over the last five years, a range of projects have focused on progressively more elaborated techniques for adaptive news delivery. However, the adaptation process in these systems has become more complicated and thus less transparent to the users. In this paper, we concentrate on the application of open user models in adding transparency and controllability to adaptive news systems. We present a personalized news system, YourNews, which allows users to view and edit their interest profiles, and report a user study on the system. Our results confirm that users prefer transparency and control in their systems, and generate more trust to such systems. However, similar to previous studies, our study demonstrate that this ability to edit user profiles may also harm the system's performance and has to be used with caution.

Users join social network sites (SNSs) for social network building and information sharing, however, little has been ascertained as to why users share information on SNSs. This study examined why SNS users share information, knowledge, and personal experiences with others on SNSs. Through an online survey, 10 motivation factors were tested with Facebook and Twitter users. The findings indicate that the motivations of SNS users in sharing information could be attributed to various aspects such as demographic characteristics, experiences of SNSs and Internet usage, as well as the characteristics and features of SNSs. SNS users could be highly motivated by the learning and social engagement aspects of SNS services. It is also found that the motivations could vary depending on the characteristics of services. The results of this study could be helpful for researchers in understanding the underlying reasons for social activities as well as for SNS developers in improving SNS services.