Is There a Need for a Relative Chronology Pattern?

[stephenhart8]

Social sciences interested in the past such as history or archæology rely heavily on understandings of time, especially when creating timelines or locating historical events in a measured chronological sequence. They have thus developed two kinds of chronology to address the sequencing of events: relative and absolute chronology.

• Relative chronology is the structuration of events or periods in relation to one another, independently of their respective dates. It is especially useful in archæology where stratigraphic or typologic sequences help understand the history of a site or to structure the periodization of an epoch. Establishing relationships between different relative chronologies (such as two different and distant stratigraphies within an archæological site, or between multiple typologies) is however difficult without absolute chronologies.
• Absolute chronology is the location in time of any particular event or the measuring of the time lapse between events. It helps establish where, in a timeline, an event occured in order to better contextualize it with regards to other contemporaneous events. Absolute chronology can be obtained by analyzing recorded events in textual sources, or with the help of modern dating sciences such as radiocarbon dating.

To fully understand past events, both types of chronology should be used together, placing events in a sequence relative to one another (relative chronology), as well as refining the sequence through precise dating (absolute chronology).

However, in the Target Model 2.2, only absolute chronology is modelled, through the class E52_Time-Span and the four properties P82a_begin_of_the_begin, P81a_end_of_the_begin, P81b_begin_of_the_end and P82b_end_of_the_end.

To address relative chronology, CIDOC CRM encourages the use of various properties linking temporal entities to each other, such as P173_starts_before_or_with_the_end_of and all the sub-properties hierarchically under it. It would also be possible to link events to larger periods with the property P9_consists_of, thus allowing to place a production event within a larger period without having to submit fixed and defined dates for the production. The dates of the periods would then be better described in a pattern documenting the period (for example presenting the conflicting dating of the period).

The issue of relative chronology can also be linked to issue #21 about modelling artistic movement, as they can be seen as periods to which production events can belong to. The discussions in issue #21 can then go beyond the sole artistic movements and encompass other important periods, such as the Bronze Age.