Patterns and Conventions for Defining OBOE-Compatible Ontologies … Based on OBOE 1.0, June, 2010

Table of Contents 1.Basic OBOE structure 2.Basic Conventions 3.Entities and Characteristics 4.Measurement standards and units 5.Measurement types 6.Context relationships 7.More patterns 8.Imports

1. Basic OBOE structure (oboe-core) Entity Characteristic Observation Measurement Protocol Standard measurementFor hasMeasurement + hasPrecision : decimal + hasMethod : anyType ofCharacteristic usesProtocol usesStandard ofEntity hasContext 1..1 * * * * * * hasValue 1..1 * * standardFor protocolFor valueFor observedBy contextFor measuredBy Note: Add ObservationCollection

1. OBOE Basic Structure (oboe-core) State the basics here …

2. Basic Conventions Conventions used by core oboe ontologies (suggested for compatible ontologies) –Class names are capitalized (e.g., Plant, Height) –Terms in names are capitalized (e.g., CarbonContent) –Classes have comments (using rdfs:comment) –Ontologies have a single rdfs:label (e.g., “oboe-units”) –Ontologies have a comment (using rdfs:comment)

2. Basic Conventions When naming entities, characteristics, and standards it is suggested they make sense in the following sentences … –The of an was recorded using the and the –The was recorded the –For example: …

3. Entities and Characteristics Entities represent distinct physical or conceptual objects –Examples include trees, plants, air, water, soil –Entities are organized into entity classes –A class denotes a set of entities (that conform to the class) Each observation has … –An observed entity Together with zero or more … –Measurements of the entity; and –Contexts represented through other observations

3. Entities and Characteristics Characteristics represent properties of entities –Examples include height, mass, speed, volume, etc. –Characteristics are also organized into classes –A characteristic is a particular occurrence of the property –For instance, a particular occurrence of the height characteristic (tied to some entity) –Each characteristic of an entity has a value A measurement asserts a value for a characteristic –A recorded value of the characteristic for the observed entity

3. Entities and Characteristics Entities vs. characteristics –Characteristics are dependent on entities … –They must be combined with an entity (the object possessing the characteristic) –They always have a value Depending on the type of characteristic … –The value can be of a primitive (like a string or numeric value) –Or another entity (e.g., tree1 nextTo tree2, hawk1 ate vole1 )

3. Entities and Characteristics Special types of entities –Primitive values are reserved for denoting basic values –Currently strings, decimals (numeric values), and Booleans

3. Entities and Characteristics Types of characteristics PhysicalCharacteristic –Any characteristic that is “physically” manifested Qualifier –A term used to modify the meaning of a physical characteristic, without changing its measurement standard –Examples include aggregates such as average, minimum, etc. Name –The globally or locally unique name assigned to the entity –For example, Plot “A”, Tree id “555”, Site “1” Type –A characteristic asserting the entity class the entity is a member of

4. Measurement standards and units Measurement standards –Represent nominal, ordinal, interval, and ratio scales –Units are a special type of standard (ratio scales) –Indexes are another special type of standard (e.g., pH)

4. Measurement standards and units Units are divided into three subclasses BaseUnit –Fundamental units, that is, not composed of other units (through products of powers of other units) –The 7 SI fundamental units are examples of base units DerivedUnit –A base unit raised to a power CompositeUnit –The product of 2 or more base or derived units

4. Measurement standards and units Units are divided into three subclasses MeasurementStandard Unit BaseUnit DerivedUnit CompositeUnit + hasPower = int hasUnit 1..1 * U hasUnit *

4. Measurement standards and units Standards (including units) typically restrict the characteristics of measurements MeasurementStandard Unit BaseUnit DerivedUnit CompositeUnit + hasPower = int hasUnit 1..1 * U hasUnit * Characteristic Measurement standardFor ►ofCharacteristic ► For example (in Manchester OWL syntax): Meter subClassOf BaseUnit and standardFor only (Measurement and ofCharacteristic only Length)

4. Measurement standards and units The oboe-units ontology Defines many common units and characteristics Drawn from LTER unit database (among other sources) Also includes some indexes Includes tricky examples such as Acre Defines unit conversions (via the UnitConversion class) –Source unit to target unit –With offset and multiplier values

5. Measurement types A measurement type … …