Direct historical approach
The direct historical approach to archaeology was a methodology developed in the United States of America during the 1920s-1930s by William Duncan Strong and others, which argued that knowledge relating to historical periods is extended back into earlier times. This methodology involves taking an archaeological site that has historical accounts relating to recent periods of occupation and then excavating it to establish continuity back into prehistoric times. The historical data then becomes the basis of analogy and homology for the study of the prehistoric communities at both the particular site and other sites in the region. The main issue with the approach is that in many parts of the world there is no direct continuity between historically documented communities and the prehistoric occupants of the region.
Read article on Wikipedia