CADAS is an online server-client survey platform that allows the active collection of polling or observational questionnaire data in various ways (e.g.: visits in CAPI-mode or Mobi-mode, phone calls in CATI-mode, web links in CAWI-mode). CADAS Mobi user (Respondent or Interviewer - depending on given data collection method) can run and complete in off line mode any questionnaire / form created with the standard CADAS questionnaire editor using the Android driven mobile devices like: tablets,