The rapid growth of the Internet offers great possibilities in the field of data-collection, as it is easier, faster, and cheaper to send questionnaires to respondents, and to communicate with respondents via the Internet than using ‘conventional’ methods. Statistics Netherlands began experimenting with data-collection via the Internet on a small scale. One experiment, for example, used a mixed-mode design comprising both an ASCII-questionnaire sent by e-mail and a paper version. Despite the fact that a lot of respondents commented on the rather antiquated layout of the ASCII-questionnaire, the results of this experiment were very promising. Meanwhile the Blaise developers had been working on Blaise Internet Services (Blaise IS), a set of tools to carry out web surveys. The Statistical Department of the Construction Industry was prepared to participate in an experiment with Blaise IS and transformed their survey for the construction industry (sent each month to a panel of companies) into an electronic questionnaire. The method used was ‘mixed mode’ because respondents could choose between either continuing receiving the paper questionnaire or receiving the electronic version of the questionnaire. The first part of this paper describes the methodology and the results of the experiment. The second part of the paper will be a more general discussion concerning Web-based interviewing and the use of Blaise IS.