Experimental studies involving the use of the World Wide Web (WWW) are becoming increasingly common in disciplines such as management information systems (MIS), marketing, and e-commerce. The focus of these studies is varied and may involve issues of human factors and interface design (Otto et al., 2000; Koufaris, 2002; Liang & Lai, 2002; Palmer, 2002), issues of information processing and search strategies (Spence, 1999; Johnson et al., 2000; Xia & Sudharshan, 2000; Chiang et al., 2004), issues of vendor trustworthiness (Grazioli & Jarvenpaa, 2000; Jarvenpaa et al., 2000; Norberg, 2003), or a myriad of other topics. Regardless of the issue being studied, data collection for online Web research often proves to be a vexing problem, and ideal research designs are frequently sacrificed in the interest of finding a reasonable data capture mechanism. In this article, we discuss some of the methodological complexities that arise when conducting Web-based experiments. We then describe an innovative, software-based methodology that addresses these problems.