Cheap, wide, shallow. Excavation gives deep information about a tiny area; field walking gives shallow information about a large one. Used together, a survey finds the places worth excavating and provides the context that a single trench cannot. Neither replaces the other.

The plough is the excavator — and the destroyer. Ploughsoil material is by definition out of stratigraphic context: it has been dragged, broken and moved. That is a real loss. But it also means the material is already disturbed, so collecting it destroys nothing further — which is why field walking is the least invasive form of archaeology there is.

Visibility is the dominant variable. Recovery depends on light, weather, soil colour, crop cover, time since ploughing, walker spacing and walker attention. Two surveys of the same field in different conditions can differ several-fold. This is why the conditions record is not paperwork — it is the calibration.

Absence is weak evidence. A blank field can mean no site, or a site under pasture that was never ploughed, or a site too deep for the plough to reach, or a site made of materials that do not survive. "We found nothing" is a statement about the survey at least as much as about the ground.

The manuring problem. Pre-modern farms carted domestic rubbish onto their fields as fertiliser, spreading broken pottery across the landscape. That produces a low, even background scatter that is real evidence — of manuring practice and field systems — but is not a settlement. Distinguishing a manuring scatter from an occupation site is the standard interpretive argument of survey archaeology, and it is settled by density, by the mix of material and by period, never by a single find.

Field Survey

Blueprints (1)

Field Walking Survey