Observer error: Are medical students good observers?

Observer error affects virtually all aspects of medicine. Our objective was to find a way to reduce it among clinical students. A minority need to be shown how to observe. A classroom exercise, repeated 6 times on separate days, using different simple objects, more than doubled the mean score on observation of visible properties of objects by a class of students in their first clinical year. Their corrected answer-slips were returned to the students at the next lecture 2 or 3 days later. Errors of omission and commission both decreased. Omission errors showed greater improvement but commission errors persisted in the class. The increment in observation seemed to be retained 5 months after tuition. Attempts were made to make a universal proforma suitable for any observation. It increased mean class score by 33% in 1994. Reducing observer error may have an educational strand.