Slider scales and radio buttons scales were experimentally compared in horizontal and vertical orientation. Slider scales lead to statistically significantly higher break-off rates (odds ratio = 6.9) and substantially higher response times. Problems with slider scales were especially prevalent in partici- pants with less than average education, suggesting the slider scale format is more challenging in terms of previous knowledge needed or cognitive load. An alternative explanation, technology- dependent sampling (Buchanan & Reips, 2001), cannot fully account for the current results. The authors clearly advise against the use of Java-based slider scales and advocate low-tech solutions for the design of Web-based data collection. Orientation on screen had no observable effect on data quality or usability of rating scales. Implications of item format for Web-based surveys are discussed.