There has been the impression amongst many observers that discussion of a grant application has little practical impact on the final priority scores. Rather the final score is largely dictated by the range of preliminary scores given by the assigned reviewers. The implication is that the preliminary and final scores are the same and the discussion has little impact. The purpose of this examination of the peer review process at the National Institutes of Health is to describe the relationship between preliminary priority scores of the assigned reviewers and the final priority score given by the scientific review group. This study also describes the practical importance of any differences in priority scores. Priority scores for a sample of standard (R01) research grant applications were used in this assessment. The results indicate that the preliminary meeting evaluation is positively correlated with the final meeting outcome but that they are on average significantly different. The results demonstrate that discussion at the meeting has an important practical impact on over 13% of the applications.