Self-administered surveys can be conducted on mobile web-capable devices, yet these devices have unique features that can affect response processes. Ninety-two adults were randomly selected and provided with mobile devices to complete weekly web surveys. Experiments were designed to address three main objectives. First, the authors test fundamental findings which have been found robust across other modes, but whose impact may be diminished in mobile web surveys (due largely to the device), by manipulating question order and scale frequencies. Second, the authors test findings from experiments in computer-administered web surveys, altering the presentation of images and the number of questions per page. Third, the authors experiment with the unique display, navigation, and input methods, through the need to scroll, the vertical versus horizontal orientation of scales, and the willingness to provide open-ended responses. Although most findings from other modes are upheld, the small screen and keyboard introduce undesirable differences in responses.