Various Web systems and services currently provide a great deal of benefits to users, with Web interaction becoming increasingly important in research and business. Such Web interaction has been realized through related technologies as interaction design, interactive information retrieval, interactive intelligent systems, personalization, user interfaces and interactive machine learning. However, each study and development in such different fields has been done independently, which might discourage us from studying Web interaction from an unified view of human-system interaction and making Web interaction more intelligent by applying AI and computational intelligence.

Guest Editors (Seiji Yamada, Tsuyoshi Murata, and Yasufumi Takama) organized an Intelligent Web Interaction Workshop 2009 (IWIf09) in Milano, Italy, last year to bring together researchers in diversified fields including Web systems, AI, computational intelligence, humancomputer interaction and user interfaces. Held jointly with 2009 IEEE/WIC/ACM International Conference on Web Intelligence (WI-2009), IWIf09 produced 14 outstanding papers - an acceptance rate of 50%, and active discussions among speakers and participants. A subsequent workshop Intelligent Web Interaction Workshop 2010 (IWIf10) will be held in Toronto, Canada in this September.

This special issue presents intelligent Web interaction as a new and promising research field. Speakers selected from among those at IWIf09 were encouraged to submit papers for this issue. The submissions were then reviewed for relevance, originality, significance and presentation based on JACIII review criteria. This special issue consists of five papers which describe excellent studies on Web interface, Web systems, Web credibility, constrained clustering for interactive Web application and graph analysis on the Web. The acceptance rate was 56%. All papers introduce promising approaches and interesting results that readers will find inspiring.

We strongly believe intelligent Web interaction has tremendous potential as a new, active field of research, and we hope this issue will motivate researchers to expand studies on intelligent Web interaction.