House for Families
DAACS Seriation Method
This page summarizes a frequency-seriation based chronology for the House for Families cellar that was developed by DAACS (see Neiman, Galle, and Wheeler 2003 for technical details). DAACS seriated ceramic assemblages, with more than five sherds, from individual excavated contexts and from stratigraphic groups -- groups of contexts that field records indicate were part of a single stratigraphic layer or deposit. Stratigraphic groups have a SG-prefix, which precedes the group number (e.g. SG01 equals Stratigraphic Group 1). DAACS used stratigraphic groups to integrate stratification as recorded in 1985 by excavators from the Virginia Research Center for Archaeology and in 1990 by a team from Mount Vernon. In some cases, Mount Vernon made finer-grained stratigraphic distinctions than did VRCA. Hence the VRCA contexts were the basis of our stratigraphic groups and the finer-grained Mount Vernon contexts were assigned to them. For example, the sediment that the VRCA excavated as context 40E was excavated by Mount Vernon in four contexts: 47E, 47F, 47G, and 47H. DAACS combined them all into a single stratigraphic group: SG04.
DAACS chose to base the seriation chronology for the House for Families site on ceramic assemblages aggregated at the level of contexts and stratigraphic groups. All the contexts and stratigraphic groups belong to the same feature: the brick-lined cellar (F01).
DAACS computed the frequency of mean-ceramic-date (MCD) types in stratigraphic groups and in individual contexts, when those contexts had no stratigraphic group assignment. The seriation chronology is derived from a correspondence analysis of these MCD-type frequencies. Seriated assemblages were assigned to phases. Phases are groups of assemblages that have similar correspondence-analysis scores and are therefore inferred to be broadly contemporary. Phases assigned by DAACS have a P-prefix that precedes the phase number (e.g. P01 equals Phase 1).
The stratigraphic relationships among stratigraphic groups and unassigned contexts are summarized in the Harris Matrix for the site. Phase assignments from the seriation are shown on the Harris Matrix in color, facilitating comparison of the seriation chronology and the stratigraphic chronology of the site.
House for Families Phases
Based on the correspondence analysis, DAACS divided the assemblages from the House for Families layers into three phases. The bulk of the assemblage from the cellar belongs to Phase 1, most of which predates the American Revolution. Phases 2 and 3 postdate the Revolution. The phases hint that the cellar was filled in two or perhaps three discrete episodes that took place for several decades, an inference made by the original excavators (Pogue and White 1991). As might be expected, the seriation placed the assemblage of ceramics recovered from a portion of a cross-section through the cellar that collapsed during excavation (47DELTA) intermediate between Phase 1 and 2.
A Seriation Chronology for the House for Families Site
The following table presents a seriation chronology for House for Families. We use the indefinite article to signify that it is not the only chronology possible, nor even the best one possible. DAACS encourages users of Archive data to help explore improvements.