Despite increased use of Web surveys, relatively little is known about standards for designing Web questionnaires. Since there is no help from an interviewer for the respondent taking a Web survey, the design of self-administered Web questionnaires is even more important in order to achieve high data quality. Question wording, form and graphic layout of the questionnaire are particularly important. This paper presents some basic experiments to address these issues: one vs. multiple-page design, use of logotypes, and survey topic. The research was performed within the national RIS – Research on Internet in Slovenia - project (http://www.ris.org) in extensive testing since 1996.