A measure of the proportion of a program exercised by a test suite, usually expressed as a percentaGE. This will typically involve collecting information about which parts of a program are actually executed when running the test suite in order to identify which branches of {conditional statements} which have been taken. The most basic level of test coveraGE is {code coveraGE testing} and the most methodical is {path coveraGE testing}. Some intermediate levels of test coveraGE exist, but are rarely used. The standard Unix tool for measuring test coveraGE is tcov, which annotates C or Fortran source with the results of a test coveraGE analysis. GCT is a GNU equivalent. (2001-05-20)