Observable feature
From Schemalet Wiki
The Observable_feature defines anything that can be observed (there may be many alternative protocols to measure them). For instance: systolic blood pressure, Diastolic blood pressure, Treatment for hypertension. These names are unique within a data set. Preferably each Observable_feature should be named according to a well-defined ontology. This class maps to XGAP Trait, FuGE Dimension_element and PaGE Observable_feature
