HT

It is our great pleasure to welcome you to ACM Hypertext 2012, the 23rd ACM Conference on Hypertext and Social Media (HT'2012) which is held at the campus of the University of Wisconsin-Milwaukee in Milwaukee, Wisconsin, from June 25-28, 2012.

The ACM Hypertext and Social Media conference is a premium venue for high quality peerreviewed research on hypertext theory, systems and applications. It is concerned with all aspects of modern hypertext research including social media, semantic web, dynamic and computed hypertext and hypermedia as well as narrative systems and applications. This year's HT'12 conference focuses on exploring, studying and shaping relationships between four important dimensions of links in hypertextual systems and the World Wide Web: people, data, resources and stories. This focus is reflected in the four tracks we have:

• Social Media (Linking people) chaired by Claudia Müller-Birn and Munmun De Choudhury

• Semantic Data (Linking data) chaired by Harith Alani and Alexandre Passant

• Adaptive Hypertext and Hypermedia (Linking resources) chaired by Jill Freyne and Shlomo Berkovsky

• Hypertext and Narrative Connections (Linking stories) chaired by Andrew S. Gordon and Frank Nack

Three keynote speakers for HT'12 present novel and stimulating ideas in this context: Steffen Staab, Jure Leskovec and Sinan Aral. Steffen Staab is a professor for databases and information systems at the University of Koblenz-Landau and director of the institute for Web-Science and Technologies (WeST). His interests lie in researching core technology for ontologies and semantic web as well as in applied research for exploiting these technologies for knowledge management, multimedia and software technology. Jure Leskovec is an assistant professor of Computer Science at Stanford University. His research focuses on mining and modeling large social and information networks, their evolution, and diffusion of information and influence over them. Sinan Aral is an Assistant Professor and Microsoft Faculty Fellow at the NYU Stern School of Business. His research focuses on social contagion and measuring and managing how information diffusion in massive social networks affects information, worker productivity, consumer demand and viral marketing.

HT'12 received 120 submissions in total, with 89 full paper and 31 short paper submissions. Each submission was reviewed by at least three reviewers, discussed by the track program committee, and finally discussed among the program chair Markus Strohmaier and the track co-chairs Claudia Müller-Birn, Munmun De Choudhury, Harith Alani, Alexandre Passant, Jill Freyne, Shlomo Berkovsky. Andrew S. Gordon and Frank Nack. We were able to accept 33 full and short papersfor oral presentation and publication in the proceedings (27 full papers, 6 short papers). Thus, the overall paper acceptance rate for HT'2012 is 27.5%. In addition to this program, we have accepted a number of posters and we will also feature an exciting program of workshops and tutorials thanks to the effort of Arkaitz Zubiaga and Carlos Solis. Thanks to Alvin Chin, we have disseminated all information about important HT'12 deadlines and activities through online social media.

The program with (free) workshops and tutorials, three keynotes, social activities and generous student grants has been made possible through the sponsorship of ACM SIGWEB. In addition, to SIGWEB's support, Hypertext 2012 has received generous support from Taylor & Francis, the publisher of the New Review of Hypermedia and Multimedia, and from our host institution, the College of Engineering and Applied Science of the University of Wisconsin-Milwaukee.

We hope that this program provides interesting ideas and novel stimuli for the attendees of HT'12, and we are looking forward to an exciting event.