[영문]The Federal regulation-writing process is vital to understanding how laws are translated into policy. This paper re-examines data on human services interest groups active in lobbying the executive branch to determine what factors influence their effectiveness. Building on findings from Hoefer (2000), structural equation modeling is used to re-analyze the original regression model of interest group effectiveness (IGE) on a sample of 127 Washington D.C.-based interest groups. Results indicate that some of the previous findings are not supported and an alternative model is proposed. A group's position, context and access to information and policymakers emerge as significant determinants of IGE. Access also mediates the impact of a group's strategy and position on IGE. Implications for practice and future research are provided