Phases
The phase is the most useful level of aggregation, representing discrete archaeological phases at a site. This is hard to define precisely, but is usually a straightforward matter of defining phases in terms of distinct cultural periods identified in the site reports. Therefore a single phase will typically aggregate data from several 'contexts'. Sometimes several different site reports exist, and the phasing inconsistencies between them will require the archaeologists inputting the data to make decisions about useful aggregations. PhaseIDs can be a maximum 9 characters. Do not use special characters or lowercase. Hyphens are OK. Typically the first few refer to the sitename. The last characters (or suffix) therefore specify the phase. Usually this is in terms of a number (1,2,3 etc), letter (A, B, C, etc), period (EN, MN, LN, etc), or culture. Ideally therefore, all phases should have a cultural assignment. In rare cases, the excavator has assigned two (and in very rare cases three) cultures, perhaps where the phase is considered transitional. Therefore 'Culture1' should always be completed. In the vast maority of cases 'Culture2' and 'Culture3' should remain NULL, but can accomodate 'additional' cultures if required (e.g. transitional between two cultures). These are not hierarchical - one should not be considered any more likely than another. The best phase chronology is 'StartBCEreported' and EndBCEreported' which comes from the site report. This will incorporate various sources evidence including subjective expert knowledge of the excavator. However, these are rarely available, so additionally 'StartBCEestimated' and 'EndBCEestimated' are generated by modelling assoicated radicarbon dates in a phase model. This is an ongoing process that incorporates as priors chronological information from other (local) phases e.g. with the same culture or period. Dates are reported as BCE, therefore negative values mean AD.
Column name	Data type	Column description
Citations	varchar	DO NOT MANUALLY ENTER VALUES !! Automatically updated from the PhaseCitation table to allow multiple values semicolon separated.
Culture1	varchar	Cultural assignment of the phase
Culture2	varchar	Alternative cultural assignment, in rare cases where (for example) the phase is transitional between two cultures
Culture3	varchar	Alternative cultural assignment, in rare cases where (for example) the phase is transitional between two cultures
EndBCEreported	int	Excavator reported end date, which incorporates various evidential sources and archaeological expertise
GMM	int	Gaussian Model Mu. Mean date of the phase, modelled as a Gaussian, using ADMUR. Reported as years BP
GMS	int	Gaussian Model Sigma. Standard deviation of the phase, modelled as a Gaussian, using ADMUR.
Period	varchar	Broad chronological period e.g. Early Neolithic (EN), Middle Neolithic (MN). Required as a primary key, so NULL is not permitted. Instead use a blank string.
PeriodNotes	varchar	More detailed information about relative chronology
PhaseID	varchar	Please see the detailed description of the 'Phases' table.
SiteID	varchar
StartBCEreported	int	Excavator reported start date, which incorporates various evidential sources and archaeological expertise
Subculture	varchar	Subcultural assignment
Type	varchar	DO NOT MANUALLY ENTER VALUES !! Automatically updated from the PhaseTypes table to allow multiple values semicolon separated.