The paper describes the pioneering experiments in Web surveys. The methodology and the results of three simultaneous surveys are described: a telephone survey of the Internet users, a mail survey of companies using the Internet and a general WWW survey of (self-selected) respondents. Specific features of the WWW respondents are emphasized and comparisons are made with other Internet users. It is confirmed that socio-demographics of WWW users across different countries are surprisingly close. The WWW survey methodology enables specific experiments related to the length of the questionnaire, exact timing of each question, tracking of the respondents and the lay-out of the questionnaire. The paper presents the key findings based on experiments incorporated in the above mentioned WWW survey. Also presented is the questionnaire markup language (QML) and the software for automatic transformation from QML to CATI, CASI, CADI format (e.g. Blaise, Interv) and to the format which can be directly applied for WWW surveys (HTML forms, Perl scripts, Java). Finally, the overall advantages and disadvantages of the WWW surveys are briefly discussed. It is argued that WWW surveys can be very effective for surveying a specific population, for mixed mode surveys and for administrative data collection. A practical application of an integrated computer assisted data collection approach is also demonstrated: the membership survey of the national Statistical Association.