# measurementQualifier

Provides additional qualification to an observation. For example, a GDP observation measures the Nominal value.

## Expected Types

| Type | Description |
|------|-------------|
| [Enumeration](https://schema.org.ai/Enumeration) | Lists or enumerations—for example, a list of cuisines or music genres, etc. |

## Used on Types

| Type | Description |
|------|-------------|
| [Observation](https://schema.org.ai/Observation) | Instances of the class [Observation](https://schema.org.ai/Observation) are used to specify observations about an entity at a particular time. The principal properties of an [Observation](https://schema.org.ai/Observation) are [observationAbout](https://schema.org.ai/observationAbout), [measuredProperty](https://schema.org.ai/measuredProperty), [statType](https://schema.org.ai/statType), [value](https://schema.org.ai/value) and [observationDate](https://schema.org.ai/observationDate)  and [measuredProperty](https://schema.org.ai/measuredProperty). Some but not all Observations represent a [QuantitativeValue](https://schema.org.ai/QuantitativeValue). Quantitative observations can be about a [StatisticalVariable](https://schema.org.ai/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](https://schema.org.ai/value) ) In the context of a quantitative knowledge graph, typical properties could include [measuredProperty](https://schema.org.ai/measuredProperty), [observationAbout](https://schema.org.ai/observationAbout), [observationDate](https://schema.org.ai/observationDate), [value](https://schema.org.ai/value), [unitCode](https://schema.org.ai/unitCode), [unitText](https://schema.org.ai/unitText), [measurementMethod](https://schema.org.ai/measurementMethod). |
| [StatisticalVariable](https://schema.org.ai/StatisticalVariable) | [StatisticalVariable](https://schema.org.ai/StatisticalVariable) represents any type of statistical metric that can be measured at a place and time. The usage pattern for [StatisticalVariable](https://schema.org.ai/StatisticalVariable) is typically expressed using [Observation](https://schema.org.ai/Observation) with an explicit [populationType](https://schema.org.ai/populationType), which is a type, typically drawn from Schema.org. Each [StatisticalVariable](https://schema.org.ai/StatisticalVariable) is marked as a [ConstraintNode](https://schema.org.ai/ConstraintNode), meaning that some properties (those listed using [constraintProperty](https://schema.org.ai/constraintProperty)) serve in this setting solely to define the statistical variable rather than literally describe a specific person, place or thing. For example, a [StatisticalVariable](https://schema.org.ai/StatisticalVariable) Median\_Height\_Person\_Female representing the median height of women, could be written as follows: the population type is [Person](https://schema.org.ai/Person); the measuredProperty [height](https://schema.org.ai/height); the [statType](https://schema.org.ai/statType) [median](https://schema.org.ai/median); the [gender](https://schema.org.ai/gender) [Female](https://schema.org.ai/Female). It is important to note that there are many kinds of scientific quantitative observation which are not fully, perfectly or unambiguously described following this pattern, or with solely Schema.org terminology. The approach taken here is designed to allow partial, incremental or minimal description of [StatisticalVariables](https://schema.org.ai/StatisticalVariable), and the use of detailed sets of entity and property IDs from external repositories. The [measurementMethod](https://schema.org.ai/measurementMethod), [unitCode](https://schema.org.ai/unitCode) and [unitText](https://schema.org.ai/unitText) properties can also be used to clarify the specific nature and notation of an observed measurement. |

---

Quoted from Schema.org 30.1, https://schema.org/measurementQualifier, under CC BY-SA 3.0. Served by the Org.AI Foundation at https://schema.org.ai/measurementQualifier.