OpenATLAS Data Model

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OpenATLAS works with data from archeological and historical sources. It uses an object-oriented approach to deal with the information. To map the "network" of data it uses classes and properties from the CIDOC CRM. The chapters below show what kind of information can be collected in the database and how they are documented.

Main entities

OpenATLAS mainly deals with 4 types of information:

  • Physical entities like archaeological sites, finds, stratigraphical units
  • Human entities like persons, groups of persons and institutions/organisations
  • Temporal entities like activities, events, phases, actions
  • Sources like articles, images, documents, that refer to other entities


Each of the above mentioned entities may be related to other ones of the same (or also of a different) class and also be subdivided into one or more subunits.

Schematic overview on the OpenATLAS Data Model

Archeological Stuff

OpenATLAS uses a 4 level hierarchy to deal with archeological information (see also the figure above).

  • On the top level there is the archeological site itself. It is defined as the whole physical thing that contains all the other subunits that form the site. This site can be a settlement, a building, a cemetery, a cave, a road or simply the place where finds haven been found.
  • An archaeological site can be composed of one or more archeological features, like graves (in case of a cemetery), walls, deposits etc. (in case of a building) or for example a conceptual unit like an unknown context of a strayfind.
  • These features are composed of their stratigraphical units like documented during excavation or logically reconstructed e.g. from older literature. This may in the case of a grave be for example the backfilling, a coffin and primary as well as secondary burials/skeletons.
  • These stratigraphical units may contain associated archeological finds like the finds from a certain stratum or the grave goods belonging to a skeleton.

Archeological Sites

An archeological site in OpenATLAS is represented by a combination of entities of certain classes from the CIDOC-CRM. The nucleus is an entity of class E18 (physical thing) that is connected to various spatial, temporal and typological entities via certain properties. To define this entity of class E18 as an archaeological site a connection to an entity of class E55 (type) is used. This type has to be (archeological) site (not to be mistaken for CIDOC-CRM class E27 "Site") or one of its subtypes.

Core-mapping of an archeological site in OpenATLAS: Example of the Early Medieval cemetery Grabelsdorf

With the above listed classes and properties the main information about an archeological site is documented. This particular combination of classes and properties is used for all archeological sites and the information is stored in the backend in the table "tbl_entities". When we now talk about "archeological site" in this wiki we mean this very combination. It will furthermore be simplified under this term for the graphical documentation.

Archeological Features

Just like an archeological site an archeological feature in OpenATLAS is represented by a combination of entities of certain classes from the CIDOC-CRM. The nucleus is again an entity of class E18 (physical thing) that is connected to various spatial, temporal and typological entities via certain properties. To define this entity of class E18 as an archaeological feature a connection to an entity of class E55 (type) is used. This type has to be (archeological) feature or one of its subtypes.

With the above listed classes and properties the main information about an archeological feature is documented. This particular combination of classes and properties is used for all archeological features and the information is stored in the backend in the table "tbl_entities". When we now talk about "archeological feature" in this wiki we mean this very combination. It will furthermore be simplified under this term for the graphical documentation.

Stratigraphical Units

Just like an archeological feature a stratigraphical unit in OpenATLAS is represented by a combination of entities of certain classes from the CIDOC-CRM. The nucleus is again an entity of class E18 (physical thing) that is connected to various spatial, temporal and typological entities via certain properties. To define this entity of class E18 as an stratigraphical unit a connection to an entity of class E55 (type) is used. This type has to be "stratigraphical unit" or one of its subtypes.

With the above listed classes and properties the main information about a stratigraphical unit is documented. This particular combination of classes and properties is used for all archeological features and the information is stored in the backend in the table "tbl_entities". When we now talk about "stratigraphical unit" in this wiki we mean this very combination. It will furthermore be simplified under this term for the graphical documentation.

Finds

A find in OpenATLAS is represented by a combination of entities of certain classes from the CIDOC-CRM. The nucleus is an entity of class E19 (physical object) that is connected to various spatial, temporal and typological entities via certain properties. To define this entity of class E19 as find a connection to an entity of class E55 (type) is used. This type has to be "find" or one of its subtypes.

With the above listed classes and properties the main information about a find is documented. This particular combination of classes and properties is used for all archeological finds and the information is stored in the backend in the table "tbl_entities". When we now talk about "find" in this wiki we mean this very combination. It will furthermore be simplified under this term for the graphical documentation.

Temporal Entities

Chronological Periods

Temporal entities are linked to archeological units via a property P86 (falls within). In detail this means that an entity of class E52 that represents the archeological unit's life span (or begin/end/creation) falls within another entity of class E52 (time span) that represents a chronological period, that itself may again fall within a larger chronological period. The life span of an archeological site may for example fall within the Carolingian Period, that itself falls within the Early Middle Ages.

Artistic/Stylistic Periods

Regarding stylistic resp. artistic periods the mapping is similar. A find's creation may for example be linked to a certain artistic style that is represented by an entity of class E4 (period), that again may fall within (P10) another superior period. An Avar belt fitting can be linked to "Late Avar 3a" that is a subunit of "Late Avar 3" that again is a subunit of "Late Avar" and so on. In OpenATLAS it is only necessary to record the relationship to the "smallest" or most precisely known unit. The relationship to further superior units is inherited automatically by their parent-child relationships.

Spatial Entities

Spatial entities are linked to archeological units via a property P89 (falls within). In detail this means that an entity of class E53 that represents the archeological unit's location falls within another entity of class E53 (place) that itself may again fall within a larger spatial unit. The location of an archeological site may for example fall within a certain administrative unit that itself falls within a district, that falls within a province and so on.

Typological Entities

It is often necessary to classify or categorize certain entities in detail. To achieve this they are linked (P2 has type) to entites of class E55 (type). Types may be super/subtypes of other types (E55 has narrower/broader term P70 of another E55). The same is to say for connections to subclasses of types like material (E57) or measurment units (E58).

References

Every entity in OpenATLAS, especially archeological ones, may be related to certain documents that refer to them. This is accomplished via property P70 (documents/is documented in). The documents may be Texts, Images, Maps (represented by an entity of class E31 - document). This is for example used for bibligraphies of archeological sites, for drawings or photographs of finds etc.

Copyright

Especially regarding photographs, drawings, texts and other entities that document a certain archeological unit and that are stored in OpenATLAS or linked to it, it is necessary to explicitly link to the copyright that applies to the document and to the right's holder. This is achieved by a link between the document (E31) to a certain copyright or licence type (E30) via the property P104 (is subject to). The copyright holder/creator of the document is represented by an entity of E39 (actor) that holds (P105) the copyright. Besides these copyright issues a document can be linked (P70 - is documented in) to another document, e.g. to record that a photograph used in OpenATLAS derives from a certain book.

Images and the documentation of their origin, copyright and right holder

Synthesis

The core of the data model is the archeological unit (site/feature/stratigraphical unit/find). This unit is connected to multiple spatial, chronological, typological, bibliographical, graphical, etc. units. Each of the units is represented by an entity of a certain CIDOC-CRM class and the link is achieved via a certain CIDOC-CRM property. Furthermore the archeological unit can be connected/linked to multiple GIS-units. They are points, lines or polygons and represented by an entry in a PostGIS table with a certain geometry-class.

mapping of an archeological unit with links to further entites and connections to GIS-tables


Historical Relations

Within the project Mapping Medieval Conflicts OpenATLAS will be used to map historical relations between persons and/or groups of persons as a basis for historical network analyses. These mappings will be based on the previous works created within the Project Eastern Alps revisited.

MappingSchemaOpenatlas.jpg