Crucially, then, recognising the interpretive nature of material evidence and the subsequent construction and use of interpretive **data** would contribute to more rigorous theory building and causal explanation in archaeology. Structuring evidence accordingly provides concepts to work to in the middle range of 'empirical theory' and consequently to construct better arguments on the basis of analysing this evidence (sensu Smith 2011Smith , 2015Ellen 2010). Nicholas and Markey (2015: 287) formulate the questions well: 'how do we know what we know about the archaeological record; and what types of evidence suffice for providing adequate "proof" for our interpretations?' Understanding archaeological evidence as physical evidence on the one hand and material evidence on the other provides the basis for establishing categories that enable arguments on a particular plane of interpretation.