| Dietary assessments, in order to deliver measurements that are reliable and repeatable, depend on the validity and reproducibility of the methods used to collate dietary information. Reproducibility is obviously a prerequisite for any test purporting to measure a dietary index but does not necessarily imply that the test itself has internal validity. On the other hand, the validity of a test, defined as its ability to measure the intended dietary variable as truthfully as possible, must also possess reproducibility in order to meet these criteria. |