<HTML>Hi Martin,
I am unsure whether you are referring to "Serpent in the Sky" as John Anthony West questions whether archaeology should be called a science or not.
In order to answer such questions it is necessary to examine firstly what is meant by the term "science". "Science" is essentially a cognitive field, where the cognitive field is defined as a sector of human activity aiming at gaining, diffusing, or utilizing knowledge of various kinds. There are two kinds of cognitive fields, one is belief fields and the other is research fields. In the latter knowledge rests squarely on observation of the real world and this field changes over time in accordance with new results generated by additional research.
Yet science itself can be divided up into "formal science" (e.g. mathematics) and "empirical science", which deals with objects of nature established by actual observation.
Yet "empirical science" can be broken down further into physical science (e.g. physics and chemistry), "natural science" (e.g. geology, biology) and "social sciences" (e.g. economics, sociology, cultural anthropology). Archaeology falls under "natural science" as it deals with the history of events of vast spans of time and the evolution of life on earth.
For a discipline to be called a science it also has to generate good quality scientific hypotheses. To test the quality of a hypothesis it must display certain characteristics: internal consistency, must not have self-contradictory statements, must call upon causes or forces at work to produce what is observed to happen, it needs to demonstrate that it really makes an advance in the state of knowledge as compared to existing hypotheses (i.e. contain observations that are not present in other works, whilst being consistent to the fundamental laws of science), and finally the hypothesis must have the power to make predictions that can be put to the test.
Repeatibility is a concept which applies to all "natural science", not only archaeology. It extends to encompass biology. Natural science is timebound. The probability of past events reoccuring in the same way is close to zero. By contrast, physical sciences like physics and chemistry deal with laws that are not unqiely positioned in time.
By these definitions along archaeology cannot be divorced from its inter-related companion scientific disciplines.
To move on to your specific example of an excavation. What tends to happen is that usually a whole site is not excavated fully nowadays. Part of the site is excavated, test trenches are dug, etc. Sites take a long time to excavated and cost a lot of money. Excavations plans are published and kept, the materials excavated are stored. Future excavators (or the same excavators after a break) can return to the site and resume excavating, drawing upon their predecessors notes. They can test the observations that were made previously against the stratigraphy and new materials uncovered. They can also go back to the original maps and re-evaluate the site plans against the straigraphy and features they see in the original excavation areas too. New and/or more advanced dating techniques and other techinques of analyses can be applied to both the old and new materials. Finally, the results obtained from sites can be compared with those from other sites both in the region and inter-regionally.
I hope this goes some way towards answering your question.
Cheers,
Mike.</HTML>
