The Harris Matrix Tool Used to Comprehend the Archaeological Past

The Harris Matrix (or Harris-Winchester matrix) is a tool developed between 1969-1973 by Bermudian archaeologist Edward Cecil Harris to assist in the examination and interpretation of the stratigraphy of archaeological sites. The Harris matrix is specifically for the identification of both natural and cultural events which make up a sites history. The construction process of a Harris matrix compels the user to classify the various deposits in an archaeological site as representing events in the lifecycle of that site. A completed Harris Matrix is a schematic that clearly illustrates the history of an archaeological site, based on the archaeologists interpretation of the stratigraphy seen in the excavations. The History of an Archaeological Site All archaeological sites are palimpsests, that is to say, the end result of a series of events, including cultural events (a house was built, a storage pit was dug, a field was planted, the house was abandoned or torn down) and natural events (a flood or volcanic eruption covered the site, the house burned down, organic materials decayed). When the archaeologist walks onto a site, evidence of all those events is there in some form. The archaeologists job is to identify and record the evidence from those events  if the site and its components are to be understood. In turn, that documentation provides a guide to the context of the artifacts found at the site. Context means that artifacts recovered from the site mean something different if they are found in the construction foundations of the house rather than in the burned basement. If a potsherd was found within a foundation trench, it predates the use of the house; if it was found in the basement, perhaps only physically a few centimeters away from the foundation trench and maybe at the same level, it postdates the construction and may be in fact from after the house was abandoned. Using a Harris matrix allows you to order the chronology of a site, and to tie a particular context to a particular event. Classifying Stratigraphic Units to Context Archaeological sites are typically dug in square excavation units, and in levels, whether arbitrary (in 5 or 10 cm [2-4 inch] levels) or (if possible) natural levels, following the visible deposit lines. Information about every level that is excavated is recorded, including depth below surface and volume of soil excavated; artifacts recovered (which could include microscopic plant remains discovered in the laboratory); soil type, color and texture; and many other things as well. By identifying the contexts of a site, the archaeologist can assign Level 12 in excavation unit 36N-10E to the foundation trench, and Level 12 in excavation unit 36N-9E to the context within the basement. Harris Categories Harris recognized three types of relationships between units--by which he meant groups of levels which share the same context: Units which have no direct stratigraphic correlationUnits which are in superpositionUnits which are correlated as parts of a once-whole deposit or feature The matrix also requires that you identify characteristics of those units: Units which are positive; that is to say, those that represent the upbuild of material to a siteNegative units; units such as pits or foundation trenches which involved the removal of soilInterfaces between those units History of the Harris Matrix Harris invented his matrix in the late 1960s and early 1970s during post-excavation analysis of site records from the 1960s excavation at Winchester, Hampshire in the UK. His first publication was in June 1979, the first edition of The Principles of Archaeological Stratigraphy. Originally designed for use on urban historic sites (which stratigraphy tends to be horrendously complex and jumbled), the Harris Matrix is applicable to any archaeological site and has also been used to document changes in historical architecture and rock art. Although there are some commercial software programs that assist in building a Harris matrix, Harris himself used no special tools other than a piece of plain gridded paper--a Microsoft Excel sheet would work just as well. Harris matrices may be compiled in the field as the archaeologist is recording the stratigraphy in her field notes, or in the laboratory, working from notes, photos, and maps. Sources Barros Garcà ­a JMB. 2004. The Use of the Harris Matrix to Document the Layers Removed during the Cleaning of Painted Surfaces. Studies in Conservation 49(4):245-258.Harris EC. 2014. Principles of Archaeological Stratigraphy. London: Academic Press.Harris EC, Brown III MR, and Brown GJ, editors. 2014. Practices in Archaeological Stratigraphy: Elsevier.Higginbotham E. 1985. Excavation Techniques in Historical Archaeology. Australian Journal of Historical Archaeology 3:8-14.Pearce DG. 2010. The Harris Matrix technique in the construction of relative chronologies of rock paintings in South Africa. The South African Archaeological Bulletin 65(192):148-153.Russell T. 2012. No one said it would be easy. Ordering San paintings using the Harris matrix: dangerously fallacious? A reply to David Pearce. The South African Archaeological Bulletin 67(196):267-272.Traxler Ch, and Neubauer W. 2008. The Harris Matrix composer, a new tool to manage archaeological stratigraphy. In: Ioannides M, Addiso n A, Georgopoulos A, and Kalisperis L, editors. Digital Heritage, Proceedings of the 14th International Conference on Virtual Systems and Multimedia:  Cyprus. p 13-20.Wheeler K. 2000. Theoretical and Methodological Considerations for Excavating Privies. Historical Archaeology 34:3-19.