The general theme of the Intelligent Data Analysis (IDA) Symposia is the - telligent use of computers in complex data analysis problems. The ?eld has matured su?ciently that some re-considerationof our objectives was required in order to retain the distinctiveness of IDA. Thus, in addition to the more tra- tional algorithm- and application-oriented submissions, we sought submissions that speci?cally focus on aspects of the data analysis process. For example, - teractive tools to guide and support data analysis in complex scenarios. With the increasingavailabilityofautomaticallycollecteddata,toolsthatintelligently support and assist human analysts are becoming important. IDA-09, the 8th International Symposium on Intelligent Data Analysis, took place in Lyon from August 31 to September 2, 2009. The invited speakers were PaulCohen(UniversityofArizona,USA)andPabloJensen(ENSLyon,France). The meeting received more than 80 submissions. The Programme Committee selected 33 submissions for publication: 18 for full oral presentation, and 15 for poster and short oralpresentation. Eachcontribution was evaluated by three expertsandhas beenallocated12pagesintheproceedings.Theacceptedpapers cover a broad range of topics and applications, and include contributions on the re?
ned focus of IDA.