[A series about the value of physical examination].

This article is the introduction to a new series in the Nederlands Tijdschrift voor Geneeskunde about the value of physical examination. Associated with this series, on the website (www.ntvg.nl) there are chapters of the new textbook on physical examination and films about carrying out physical examinations. Although physical examination is an essential part of the diagnostic process, often little attention is paid to the correct execution of the examination and there is insufficient knowledge of the value of the findings. The diagnostic process usually involves analysing all the information from the patient's history and a physical examination. However, research has only been done on the value of specific tests and even that is very limited. The most important measure we use for the results of a physical examination is the likelihood ratio, which shows how the likelihood of presence or absence of a disease changes depending on the examination results.