Providing interpretative comments on reports, particularly those for primary care physicians is an important part of our job. Few clinical biochemists (whether medical or scientific) receive significant training for this. Most work in isolation, and few receive feedback on the utility of their comments. Surveys show an extremely wide divergence of opinion and comment even on apparently straightforward sets of abnormal results. Some comments are regarded as highly inappropriate when assessed by peer review. There is a need for further education and training in this area, concentrating as much on 'how to comment' as on 'what to comment'. There is also a need to establish some form of quality assurance for this important part of the post-analytical phase. A pilot External Quality Assurance Scheme (EQAS) is now being established.