The main objective of this study is to evaluate various algorithms and display concepts of the Warning Decision Support System - Integrated Information (WDSS-II). The participants were operational forecasters from the National Weather Service Weather Forecast Office (WFO) in Norman, Oklahoma. Several training sessions, real-time observations during ten severe weather events between May and June 2004, and surveys were conducted in this study. Feedback, suggestions, and criticisms from the forecasters regarding the system were collected and analyzed. The results of the study are presented in this paper.