The models (see Section 3) seek to predict the chances of a drug clearing at least Phase II of an FDA (Food and Drug Administration) trial. The bimodal dependent variable is constructed by classifying all trials with a 'Completed' Status in Phase III or Phase IV as a 'Pass' (0 value) categorization, and all trials that have the Status of 'Terminated', 'Suspended', etc. in Phase II/ III/ IV with a 'Fail' (1 value) categorization, as reported against the trial ID (NCT ID) in the . This method of classification is not very different from earlier work . Since we categorize only 'Completed' trials from Phase III and up as a 'Pass', while the 'Fail' category includes negative trials from Phase II/ III/ IV, the model is expected to predict the possibility of the overall success of a particular single drug trial to move beyond Phase II, and not necessarily the ability of a compound to transition across specific phases. A separate model is presented that predicts the ability of a compound to clear Phase II. In this model, the 'Fail' category includes data from Phase II and above.