The analysis verification tests provide data that define the accuracy of the damage tolerance analysis tools relative to their ability to predict the crack growth behavior of the structure under operational conditions.  In essence, these tests are conducted to verify individual or collective elements of the damage integration package that will be used to conduct damage tolerant life analysis studies.  Analysis verification tests include those tests that are used to verify stress-intensity factor calculations, residual strength methods, crack growth calculations, and test spectrum truncation procedures.  The tests range in difficulty from constant amplitude tests on fairly simple structural geometries to flight-by-flight load type tests conducted on structures that simulate isolated design features contained in full-scale structural components.  These tests are typically conducted during the design analysis and development testing phase of the contract prior to testing the full-scale structure and major components.  Additional testing may also be necessary subsequent to the results of the full-scale flight and ground tests to support interpretation and evaluation of cracking problems.