- Medical research projects that involve any aspect of the collection, summarization, analysis and/or interpretation of clinical quantitative information require statistical support. This input may be provided by the clinicians themselves if properly trained, but is most appropriately and commonly achieved by a relationship with a biostatistician. The biostatistician can be an assistant, a consultant, or a colleague co-investigator. The role of the biostatistician in the research endeavor is one that is partially dictated by the nature of this relationship, but also is one that has evolved considerably in the recent past. This paper reviews the role of the biostatistician in terms of the potential contribution to the research, with special attention to the evolution of this role in light of the fast changes in computation and in statistical methodology. Finally, a method for biostatistical critical appraisal of the biomedical literature is proposed.