The AlpineBits^® DestinationData Ontology

The AlpineBits® Ontology formalizes the worldview shared by AlpineBits members over concepts of the tourism domain. It supports semantic interoperability between members through a technology-agnostic conceptual model.

The ontology documents the members' agreement at the conceptual level and drives the development of the AlpineBits®, while the API specification documents their agreement at the technological level is defined in the subsequent chapters.

A user of the AlpineBits® may use this ontology as a reference to interpret the real-world semantics of the data the user will consume from a SERVER, thus avoiding interoperability issues.

Modeling Language: OntoUML

The AlpineBits® Ontology is designed using the OntoUML, an ontologically well-founded extension of the UML Class Diagram that can be used to represent a domain of interest from a computationally independent perspective.

OntoUML consists of a set of stereotypes applicable to classes, associations, and attributes, with precisely defined formal semantics derived from the Unified Foundational Ontology (UFO), an axiomatic formal theory based on theories from analytic metaphysics, philosophical logic, cognitive psychology, and linguistics.

An important meta-property of an OntoUML class stereotype is dubbed rigidity.

• A rigid class statically classifies its instances, i.e., an instance of a rigid class must instantiate it throughout its whole existence. Examples include Person, Animal, Organization, Contract, and Marriage.

• An anti-rigid class dynamically classifies its instances, i.e., an instance of an anti-rigid class at a given point in time may cease to be so later on. Examples include Teenager, Adult, Student, and Spouse.

Another fundamental meta-property for classes is sortality.

• a sortal class is one whose instances share a common identity principle, where the sortal class must either provide this principle or inherit it from a superclass. Examples of classes that provide identity principles include Person, House, and Car, and those that inherit such principles include Student, Man, Adult, Town House, and Sports Car.

• a non-sortal class is one whose set of instances includes entities complying with different identity principles. Examples include Agent, which classifies instances of sortal classes Person and Organization, and Physical Object, which classifies instances of sortal classes Car and House (among others).

The OntoUML class stereotypes used in the AlpineBits® Ontology are:

• «kind»: a rigid sortal (identity provider) class that classifies object-like entities. Examples of typical kinds include Person, Organization, Car, and House.

• «relator»: a rigid sortal (identity provider) class that classifies relational entities, also known as relationships. Examples include Marriage, which relates two instances of Spouse; Contract, which relates instances of Party in the context of formal agreements; and Enrollment, which relates an instance of Student to an instance of Educational Institution.

• «quality»: a rigid sortal (identity provider) class that classifies entities that represent aspects of other entities and are measurable in some value space (i.e., conceptual space). A quality may be used to compare individuals, on the basis of the value it takes in a certain quality space (for example, a mass in the kilogram scale, or a position within the RGB spectrum). Examples include Weight (as in the weight of a person), Name (as in the name of an organization), Color (as in the color of a car), and Duration (as in the duration of a concert).

• «subkind»: a rigid sortal class that inherits its identity from another sortal. Examples of subkinds include For-Profit Organization, Fiat 500, and Civil Marriage.

• «role»: an anti-rigid sortal class whose instantiation depends on a relational condition. Examples include Student, Artist, and Legally Recognized Marriage.

• «phase»: an anti-rigid sortal class whose instantiation depends on a change in an intrinsic property. For example, Child may be a subclass of Person whose instances are people up to 12 years old.

• «category»: a rigid non-sortal class that classifies entities of different sorts. Examples include Agent, which classifies instances of both Person and Organization; and Animal, which classifies instances of different species of animals, including Felis Catus (domestic cat), Canis Lupus Familiaris (dog), and Panthera Leo (lion).

• «roleMixin»: an anti-rigid non-sortal class that classifies roles playable by individuals of different sorts. Examples include Organizer, as the agent that organizes some event, and Author, as the agent that holds the right to some intellectual property.

• «type»: a rigid class that classifies entities that have instances themselves (i.e., other classes). Examples include Car Model, whose instances may include Fiat 500 and Tesla Model S; and Event Type, whose instances may include Musical Event and Sports Event.

• «datatype»: a class that classifies values contained in a well-defined conceptual space, e.g., integer and real numbers (in their respective sets), Mass in Kilograms, and RGB Color.

• «enumeration»: a class that classifies values within a discrete finite conceptual space. Examples include Day of Week, whose possible instances are the 7 days of the week; and Driver License Category, whose possible instances are A, B, C, D, and E.

The OntoUML association stereotypes used in the AlpineBits® Ontology are:

• «mediation»: an existential dependence relation that connects relators to the entities they bind. For example, instances of the relator Marriage mediate instances of the class Spouse; instances of the relator Contract mediate instances of the class Contract Party.

• «characterization»: an existential dependence relation that connects an aspect (e.g., a quality) to the entity it characterizes. For example, instances of the class Color characterize instances of the class Physical Object.

• «material»: a relation that connects entities based on something dependent on these entities. For example, instances of the association "married with" connect instances of the class Spouse that have a marriage relationship dependent on them.

• «componentOf»: a part-whole relation that connects objects with their functional components. Examples include the composition relation between an instance of Car and the instance of Engine installed in it; the relation between an instance of Human Body and an instance of Heart.

• «historicalDependence» a relation that binds entities because of an event that happened in the past. For example, an instance of Place may be related through a historical dependence to an instance of Image Object that is a representation of that place at a point in time.

• «instantiation»: a relation between two classes representing that instances of one may be classified by instances of the other. For example, the relation between Car and Car Model, which represents that every car is an instance of a car model.

Ontology Description

The figure below depicts the taxonomy of named entity defined by the AlpineBits® Ontology designed to represent the individuals and types present in the ontology’s domain:

All classes of entities characterized by description information in the AlpineBits® Ontology specialize Named Entity. Named Entity has the following properties: abstract, a short description of the individual; description, a description of the individual more thorough than an abstract; name, the name of the individual; short name, the short version of the name of the individual (e.g., an abbreviation); url, a link that leads to additional information regarding the individual.

The additional classes of individuals and types in the figure above are described in the following sections.

Categories and Features

A Category is a type that classifies entities in the tourism domain. Examples of categories include "music event", which classifies the South Tyrol Jazz Festival 2018, and "public space", which classifies the Piazza Walther Von der Vogelweide.

A Category may classify one or more Named Entities of different types. For instance, "music event" classifies only instances of event plans, while "public space" classifies instances of venue and trail.

A Feature is an attraction or anything that can be present in a Named Entity in the tourism domain. Examples of features include, "auditorium" as in venues that present some available auditorium, "food and drinks" as in events that present food selling stations, or "parking space" for places that present a dedicated parking area.

A Snowpark Feature is a snowpark-specific feature. Examples of snowpark features include "rail" and "ramp", these present in snowparks that enable the practice of special maneuvers in winter sports.

Categories and features can be organized into hierarchies where being an instance of a child category implies being an instance of the parent category and presenting a child feature implies presenting a parent feature. For example, an instance of the event plan category "conference" is also an instance of its parent category "business event". Moreover, a venue that presents the feature "olympic size swimming pool" also presents the its parent feature "swimming pool".

Agent

An individual who bears mental attitudes and is capable of performing actions and perceiving events.

An Agent is either a Person, such as Albert Einstein, Marie Curie, Lionel Messi, and Serena Williams, or an Organization, such as Apple, Facebook, the AlpineBits Alliance, and the Free University of Bozen-Bolzano.

An Agent can play several roles within the touristic domain, namely the Organizer, Sponsor, Publisher, or Contributor of an event, the License Holder or the Author of a media object, and the Area Owner of a mountain area.

A fragment of the ontology depicting Agent and its properties is presented below:

In addition to the attributes inherited from Named Entity, Agents have a property named contact points, which identifies a list of Contact Points one can use to get in touch with an Agent.

A Contact Point informs how to contact an Agent, namely its email address, telephone number, and physical address, but also when to do it by means of the available hours property.

Contact Point information is relevant for tourists who want to contact the owner of a mountain area to know about its slopes conditions, or for customers who want to contact an event’s organizer about ticket prices.

Media Object

An object that materializes creative works into a digital format to enable processing and sharing.

Three disjoint types of Media Objects are identified in the ontology, namely Audio Object, e.g. an audio file containing a recording of a song, Image Object, e.g. an image file depicting a lift, and Video Object, e.g. a video file containing a recording of a musical performance.

A fragment of the ontology depicting Media Object, its properties, and subtypes is shown below:

In addition to the attributes inherited from Named Entity, Media Object is characterized by content type, which refers to the Media Types (formerly known as MIME Types) defined by the Internet Assigned Numbers Authority (IANA).

A Media Object, or more precisely, the creative work embedded in it, can have its rights owned by an agent, termed the License Holder. Apart from the license holder, a creative work can also have an Author who may not hold the licensing right over its creation. Additionally, it may be available for reuse by others according to a License Type, such as the Creative Commons 1.0 Universal.

A Media Object often depicts a Named Entity, such as events, event venues, lifts, ski slopes, and snowparks. This depiction is captured in the ontology by means of the historical dependence between Named Entity and Media Object.

Place

An individual that has a fixed physical location and can be localized within a Global Positioning System (GPS) (adapted from Schema.org). Examples of places include a town square, a stadium, a ski slope, a gas station, and a park.

A Place may go through two phases: In Operation and Permanently Closed. The first classifies places that are functioning, regardless if they are currently open or not. The second classifies those that have terminated its operations.

Place specializes Named Entity and thus, inherits all of its attributes.

Place is additionally characterized by the attributes address, how to arrive, and openingHours: address represents the physical address of a place; how to arrive is a textual description on how to arrive at a place; and opening hours identifies when a place is (or should be) open.

A Place may be physically connected to other places and give access to them. For instance, the Falzeben Gondola at Merano 2000 gives access to the Falzeben I and Wallpach slopes. In the ontology, this relation is captured by the connections self-type association defined for Place.

Notice, however, that the connection relation is non-symmetric in cases where two places are only connected in one direction. For example, A Lift may give access to a Snowpark, but the Snowpark (due to the descent, for instance) may not give access back to the Lift.

A fragment of the ontology centered around the Place concept, its properties, and subtypes is shown below:

The GPS information that can be associated to a Place is represented by means of the Geometry quality, which is sub-classified into the following subtypes according to its geometrical shape: Point, Multi Point, Line String, Multi Line String, Polygon, and Multi Polygon. Instances of Geometry must instantiate exactly one of the aforementioned subtypes.

The coordinates attribute in the Geometry class is the list of points that compose the geometry.

Event, Event Series and Venue

An Event Plan is a plan established by one or more Organizers aiming some Target Audience (adapted from the Core Public Event Vocabulary). Event Plans are planned to be held at some particular date and time.

Examples include the Südtirol Jazz Festival 2018, the South Tyrol Free Software Conference organized in 2019, the Bolzano Christmas Market of 2019, and a Serie A match between Juventus and Napoli.

In addition to the attributes inherited from Named Entity, an Event Plan has the attributes start date, end date, in-person capacity, online capacity, participation url, registration url, and recorded: a start date which describes when the event is planned to start; an end date which describes when the event is planned to end; in-person capacity which describes the event’s capacity for in-person attendance; online capacity which describes the event’s capacity for virtual attendance; participation url which is the URL for virtual attendance in the event; registration url which is the URL for registration to the event; and recorded which describes whether the event is planned to be recorded.

Event Plans can be In-Person, Virtual, or Hybrid, depending on whether they participants are planed to join the event in-person, virtually, or by either of these options.

In-Person Events and Hybrid Events happen at one or more places, which are dubbed its Venues. For instance, the venue of Bolzano Christmas Market in 2019 was Piazza Walther.

Virtual Events and Hybrid Events are supported by one or more Streaming Platforms. For instance, the South Tyrol Free Software Conference organized in 2021 was streamed to Element and YouTube.

An Event Plan may involve several Agents, i.e. persons or organizations, in different ways. An Organizer plans the event and is legally responsible for it; the Publisher provides data about it; a Sponsor supports its organization, usually by making financial contributions; and a Contributor actively participates in the event, such as a presenter, a singer or an expositor.

Events may be composed of smaller events. For instance, the Südtirol Jazz Festival 2019 was composed of over 30 individual concerts. This type of event is classified as a Composite Event in the ontology, while those without sub-events are deemed Simple Events.

An Event Plan is in one of two phases, namely Published and Cancelled. The former refers to those whose plans are or were valid, while the latter refers to those that have been canceled.

Many Event Plan Categories can classify Event Plans that share common characteristics they identify, such as "music event" or "sports event".

Each Event Plan may instantiate a special type of Event Plan Category called Event Series. An Event Series is a kind of "template" for recurrent Event Plans that are referred to as its editions. Examples include the Olympics, which is organized every 4 years, and the Bolzano Christmas Market, which is organized every year, and the Food Truck Weekend, which is organized sporadically in Trento.

It is not possible for an Event Plan and one of its parts to be editions of the same Event Series. However, an Event Plan and its parts may be editions of distinct Event Series. For example, the "South Tyrol Jazz Festival 2021" may be an edition of the "South Tyrol Jazz Festival" series, while the presentation of "András Dés Rangers on 04/07/2021", its sub-event, may be an edition of the "András Dés Rangers European Tour 2021".

The frequency in which an Event Series is organized is captured in the ontology by the homonymous attribute.

A fragment of the ontology focused on the concepts of Event Plan, Event Series, and Venue is shown below:

Mountain Areas

A Mountain Area is a geographical region in which alpine sports and activities can be performed, such as skiing, snowboarding, climbing, and hiking.

Examples include Dolomiti Superski, located in South Tyrol, Italy, Zermatt Matterhorn, located in Switzerland, and St. Anton Arlberg, located in Austria.

An excerpt of the ontology regarding Mountain Area and its properties is shown below:

As a particular type of Place, Mountain Area inherits all of its attributes and relations, which includes address and GPS-related properties.

Instances of Mountain Area are alpine regions that contain other places of interest, among which instances of Lift and Trail are commonly found.

Mountain Areas may contain other mountain areas. This is the case of Dolomiti Superski and Ortler Skiarena, which contain several smaller areas in South Tyrol. In such cases, the broader area contains, by transitivity, every Lift and Trail within its contained areas.

Note, the composition of mountain areas is:

• irreflexive: an area cannot contain itself;

• transitive: if area X contains area Y and area Y contains area Z, then X contains area Z;

• antisymmetric: if area X contains area Y, area Y cannot contain area X.

A Mountain Area is usually owned by an organization. For instance, the Merano 2000 area is owned by the Merano 2000 Funivie Spa organization.

Trails and Lifts

A Trail is a physical path where sporting activities can be performed. Trails are classified according to the sporting activities offered, such as hiking trails, ski trails, and biking trails, which support hiking, skiing, and biking respectively. This version of the standard distinguishes between two types of trails, namely Ski Slope (aka ski trail) and Snowpark.

Trails are rated according to how challenging it is to practice a sport on them. This characteristic is captured by means of a general Difficulty level, which can be projected in different scales. For instance, a Ski Slope’s `Difficulty can be valued according to the European or American Systems, as in the Falzeben I slope of the Merano 2000 area is rated blue (or easy) in the european system.

A Ski Slope is a Trail, usually on a hill, where people can ski and snowboard.

A Snowpark is a Trail specially designed to allow skiers and snowboarders to perform freestyle tricks by providing them with special features, such as jumps and rails.

A Lift is a machine designed to transport people uphill, often being used to transport skiers in mountain areas. Lifts may be of several types, such as chairlifts, gondolas, and cableways.

A fragment of the ontology that formalizes Trail, Ski Slope, Snowpark, and Lift is presented below:

Snow Measurement

A relevant piece of information for alpine tourists during the winter season is the snow condition of mountain areas and ski slopes. This is captured in the ontology by means of the Snow Measurement concept, a relator that describes the result of a measuring activity performed by an Agent, at a particular Place, in a given point in time (date).

An excerpt of the ontology describing Snow Measurement is shown below:

Note that Snow Measurement specializes Geospatial Feature. This means that its instances may be localized using GPS Geometries of any shape.

A Snow Measurement identifies the following descriptive properties:

• base snow: the height of snow in the vicinities of the measurement location

• base snow range: the variation of the base snow measurement in the vicinities of the measurement location

• groomed: indicates whether or not the snow has been groomed in the vicinities of the measurement location

• primary surface: the main type of snow found in the vicinities of the measurement location

• secondary surface: the secondary type of snow found in the vicinities of the measurement location

• snow making: indicates whether or not the snow in the vicinities of the measurement location has been artificially produced

• snow over night: the height of snow accumulated in the previous night in the vicinities of the measurement location

• storm total: the height of snow accumulated from the last snowstorm in the vicinities of the measurement location