Advances in our understanding of ore genesis provide practical insights that improve 'deposit modelling,' leading to increased confidence in resource/reserve estimation. Exploration data, particularly at the deposit appraisal stage, must be directed more toward developing a satisfactory geological information base for estimation purposes. This geological information base, including regional/property/deposit geology mineralogy, mineralization styles, continuity and ore deposit models, are discussed in terms of their potential contributions to "improved" mineral inventory estimates.