They collected and analyzed organic materials — paleofeces, seeds, charred plant fragments — that previous researchers had either ignored or not had the analytical methods to interpret.

They used radiocarbon dating systematically to establish the chronology of cave use.

The finding that emerged most clearly from this systematic work was that the cave had been used for an extended period — measured in centuries — not as a place of occasional or accidental human presence but as a systematic industrial operation.

The distribution of mining marks, the quantities of mussel shell scrapers, the spatial patterning of torch fragments, and the analysis of what the miners were eating all supported a picture of organized, repeated, intentional mineral harvesting.

Watson also used experimental archaeology — attempting to replicate ancient techniques — to test hypotheses about the ancient mining practice.