Observation

Instances of the class Observation are used to specify observations about an entity at a particular time. The principal properties of an Observation are observationAbout, measuredProperty, statType, [[value] and observationDate and measuredProperty. Some but not all Observations represent a QuantitativeValue. Quantitative observations can be about a StatisticalVariable, which is an abstract specification about which we can make observations that are grounded at a particular location and time. Observations can also encode a subset of simple RDF-like statements (its observationAbout, a StatisticalVariable, defining the measuredPoperty; its observationAbout property indicating the entity the statement is about, and value ) In the context of a quantitative knowledge graph, typical properties could include measuredProperty, observationAbout, observationDate, value, unitCode, unitText, measurementMethod.

Properties from Observation

Property Expected Type Description
marginOfError QuantitativeValue A marginOfError for an Observation.
measuredProperty Property The measuredProperty of an Observation, typically via its StatisticalVariable. There are various kinds of applicable Property: a schema.org property, a property from other RDF-compatible systems, e.g. W3C RDF Data Cube, Data Commons, Wikidata, or schema.org extensions such as GS1's.
measurementDenominator StatisticalVariable Identifies the denominator variable when an observation represents a ratio or percentage.
measurementMethod DefinedTerm, URL, MeasurementMethodEnum, Text A subproperty of measurementTechnique that can be used for specifying specific methods, in particular via MeasurementMethodEnum.
measurementQualifier Enumeration Provides additional qualification to an observation. For example, a GDP observation measures the Nominal value.
measurementTechnique Text, DefinedTerm, URL, MeasurementMethodEnum A technique, method or technology used in an Observation, StatisticalVariable or Dataset (or DataDownload, DataCatalog), corresponding to the method used for measuring the corresponding variable(s) (for datasets, described using variableMeasured; for Observation, a StatisticalVariable). Often but not necessarily each variableMeasured will have an explicit representation as (or mapping to) an property such as those defined in Schema.org, or other RDF vocabularies and "knowledge graphs". In that case the subproperty of variableMeasured called measuredProperty is applicable. The measurementTechnique property helps when extra clarification is needed about how a measuredProperty was measured. This is oriented towards scientific and scholarly dataset publication but may have broader applicability; it is not intended as a full representation of measurement, but can often serve as a high level summary for dataset discovery. For example, if variableMeasured is: molecule concentration, measurementTechnique could be: "mass spectrometry" or "nmr spectroscopy" or "colorimetry" or "immunofluorescence". If the variableMeasured is "depression rating", the measurementTechnique could be "Zung Scale" or "HAM-D" or "Beck Depression Inventory". If there are several variableMeasured properties recorded for some given data object, use a PropertyValue for each variableMeasured and attach the corresponding measurementTechnique. The value can also be from an enumeration, organized as a MeasurementMetholdEnumeration.
observationAbout Place, Thing The observationAbout property identifies an entity, often a Place, associated with an Observation.
observationDate DateTime The observationDate of an Observation.
observationPeriod Text The length of time an Observation took place over. The format follows `P[0-9]*[Y|M|D|h|m|s]`. For example, P1Y is Period 1 Year, P3M is Period 3 Months, P3h is Period 3 hours.
variableMeasured Property, StatisticalVariable, PropertyValue, Text The variableMeasured property can indicate (repeated as necessary) the variables that are measured in some dataset, either described as text or as pairs of identifier and description using PropertyValue, or more explicitly as a StatisticalVariable.

Instances of Observation may appear as a value for the following properties

Property On Types Description
diseaseSpreadStatistics SpecialAnnouncement Statistical information about the spread of a disease, either as WebContent, or described directly as a Dataset, or the specific Observations in the dataset. When a WebContent URL is provided, the page indicated might also contain more such markup.