LinkedEarth Ontology
At its most fundamental level, the LinkedEarth Ontology allows us to not only define terms commonly used to describing a paleoclimate dataset (e.g., variable, uncertainty, calibration) but also to specify the relationship among those terms (e.g., a variable has uncertainty). As such it allows us to make inferences, support complex queries, as well as perform quality control on the data.
How useful is the ontology?
One of the most practical aspects of the ontology is to allow to query the data. For instance, the following query searches the entire database for coral d18O records that have been interpreted to represent temperature (limit =10).
{{ #ask:
[[Category:Dataset_©]]
[[IncludesPaleoData_©.FoundInMeasurementTable_©.IncludesVariable_©.MeasuredOn_©::<q>[[Category:Coral]]</q>]]
[[IncludesPaleoData_©.FoundInMeasurementTable_©.IncludesVariable_©.InterpretedAs_©.Name_©::T]]
| ?IncludesPaleoData_©=PaleoData
| format=broadtable
| limit=10
}}
A quick look at the code above describes the hierarchy of a dataset on the wiki (and in the corresponding LiPD file). In essence, the query asks the database to find the datasets(Category:Dataset_©),
- which include (Property:IncludesPaleoData_©) PaleoData (Category:PaleoData_©),
- that are found in (Property:FoundInMeasurementTable_©) a table (Category:MeasurementTable_©),
- that include ( Property:IncludesVariable_©) variables (Category:Variable_©).
These variables need to fit two criteria:
- to be measured on (Property:MeasuredOn_©) an archive of type coral (Category:Coral)
- and for the variations to have be interpreted as (Property:InterpretedAs_©) temperature (or T)
The sections below describes the difference between properties and categories on the wiki.
Remember that no formal knowledge about ontologies is required to use and contribute to the wiki.
