1. A method for determining a direct hydrocarbon indicator from seismic data comprising: acquiring seismic data associated with a plurality of seismic data sensor locations; selecting a hydrocarbon associated exemplar data group and a non-hydrocarbon associated exemplar data group from the seismic data associated with a plurality of data sensor locations to obtain hydrocarbon exemplar group members and non-hydrocarbon exemplar group members; calculating hydrocarbon exemplar data group probability density function values, using a processor, and non-hydrocarbon exemplar data group probability density function values over an attribute space based on selected distribution values of seismic data attributes of the hydrocarbon exemplar group members and non-hydrocarbon exemplar group members; and applying a Bayesian inversion to determine exemplar data group membership probability for seismic data associated with at least one of the plurality of seismic data sensor locations by comparing distribution values of the seismic attribute values of the seismic data associated with at least one of the plurality of seismic data sensor locations to at least one of the calculated hydrocarbon exemplar data group probability density function values and non-hydrocarbon exemplar data group probability density function values.