COMPSTAT : proceedings in computational statistics; 16th symposium held in Prague Czech Republic 2004 Statistical computing provides the link between the statistical theory and applied statistics. As at previous COMPSTATs the scientific programme covered all aspects of this link from the development and implementation of new statistical ideas through to user experiences and software evaluation. Following extensive discussions a number of changes have been introduced by giving more focus to the individual sessions involve more people in the planning of sessions and make links with other societies as Interface of International Federation of Classification Societies involved in statistical computing. The proceedings should appeal to anyone working in statistics and using computers whether in universities industrial companies government agencies research institutes or as software developers