Ontobras 2019 - Tutorial: Relationships and events: a general theory of reification and truthmaking
By Nicola Guarino 
*My own comments are marked with an asterisk

Reifying relationships allows us to talk of:
- their nature
- the way they change in time
etc.

In Data Modeling, this has also been clear from the early stages. For instance, ER (Chen) includes a syntactical representation of relationship reification (diamond).

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Relation vs. Relationship

- Common view: relation is a class of tuples.
- Chen: a  relationship type is a set of tuples. Relationship = tuple
*more on his slide
*Relationship is what UFO calls Relator

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He presented an example of an ER model with an association class.
Attributes in an association class are just syntactic annotations: no new entities is introduced in the domain of discourse
Constraints on the way the relation may hold cannot be expressed

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Cardinality ambiguity is a common problem in n..n relations. This problem is targeted in the proposal of Guizzardi 2005, which defines Relators.

Example of different kinds of medical treatments, which deals with single-tuple vs. multiple-tuple cardinality constraints.

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What to reify?

The ontological answer: those entities that are responsible for the truth of our propositions. E.g. it is the color of the rose that makes the statement "This rose is red" true.

Thus, ontological analysis is the search for truth makers

Truth making patterns: a systematic approach

- property and their truthmakers

(more in his slide)

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Linguistic evidence of property reification: adjective nominalization
E.g. Mary is beautiful
A state: Mary's being beautiful
A fact: The fact that Mary is beautiful
As a quality: Mary's beauty

Mary's being beautiful is raw and wild - we cannot say that!
But we can say: Mary's beauty is raw and wild.

Moltmann, F. (2013) Abstract Objects and the Semantics of Natural Language.

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The truth maker of a property P, holding fo x, is a suitable y in virtue of which P(x) holds. E.g. it is because of Mary's beauty that makes Mary beautiful.
in virtue of y = in virtue of the existence of y
E.g.
rose(a) holds in virtue of the existence of a certain rose denoted by a (x = y in this case)
red(a) holds in virtue of the existence of a certain redness event (actually, a state) or the quality of being red.
*I asked if a quality could be the truth maker and he said yes, but the quality is a weak truth maker in some cases while the state is a strong one (e.g. Mary's height - remember that the mere existence of the truth maker should be enough to satisfy the true. This is not the case of height in the sentence "Mary is tall", but it is for the state of being tall).

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Strong truth making: P(x) holds in virtue of the mere existence of a certain y
Weak truth making: P(x) holds in virtue of the way a certain y is
E.g. A Rose that in t1 is red and in a t2 is brown:  different strong truth makers (the two states); same weak truth maker (the quality).

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Classifying properties according to their truth makers

Descriptive properties hold in virtue of how their arguments are: Red(x), Tired(x), Married(x)
They have qualities as weak truth makers and events as strong truth makers

Non-descriptive properties hold in virtue of what their arguments are, i.e. their nature and structure: Apple(x), Person(x)
They may have objects as weak or strong truth makers, and events as strong truth makers.

Internal property vs External property
An internal property does not require external entities (e.g. Red(x), Apple(x)) while an external property do (Married(x), Father(x)).

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He showed OntoUML models exemplifying how the color property can be reified as a Quality:
- Color (<<quality>>) inheres in Rose (<<kind>>)
Then he showed two other patterns.
- One connecting a Rose (<<kind>>) and a Color Occurrence (<<event>>)
- Complete pattern: Color (<<quality>>) inheres-in Rose(<<kind>>) participates-in Color Occurrence (<<event>>).

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Classifying Relations

- Guizzardi's original distinction regarding relations: Material vs Formal relations

- Classifying relations according to their truth makers

Descriptive relations hold in virtue of  how their arguments (relata) are: Heavier(x,y); Work(x,y)
weak truth makers: qualities inhering on the relata or their parts
possible strong truth makers: objects or events

Non-descriptive relations hold in virtue of what their arguments are, i.e. their nature and structure. E.g. Part(x,y), Depedent(x,y); inheres-in(x,y); Born-in(x,y)
weak truth makers: qualities inhering on the relata or their parts
possible strong truth makers: objects or events

Internal relations are such that each of their weak truth makers components is internal to one argument (i.e. there is no dependence in any external entity):
E.g. Heavier(x,y)

External relations are such that some of their weak truth makers components is dependent on some other argument.
E.g. Works-for(x,y)

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Mathias mentioned an example that is interesting: someone is in love with a fictional character that is inside her mind. Is this an external relation? Nicola answered it is something to be reflected on, since this work is new and ongoing.

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*Aspectual slice of an entity is what UFO (Guizzardi 2005) calls qua-entity

The qua-entities may evolve and change. In other words, new qualities may be included there.

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Relationships as variable embodiments of qualities (Kit Fine) 

At each time, a relationship is constituted by a mereological sum fo relational qualities:
- a core nucleus of essential qualities, that can have different values (qualia) at different times;
- a shell of non-essential qualities depending on the nucleus, that can cease to exist or come into being the life of the relationship.

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Each relationship (relator) is an instance of a rigid kind, which determines the range of values for the qualities.

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Truth making Patterns for Internal Descriptive Relations (Comparative Relations)
(The ER 2018 explains the existing UFO-based truth making patterns)


*Important: Seeking for the truth maker is what motivates the emergence of each new pattern.

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*There was a lively discussion about the need for this kind of relationship (relator). Nicola gave us a good example (The distance of the moon. We can talk about this relationship, thus it may be reified).

Mathias brought a new interesting example: "Mathias is taller than Napoleon". Since Napoleon is dead, this complicates things a bit, but we are able to model it adding other concepts. Perhaps we may say there is no relationship between Mathias and Napoleon. 

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Truth making patterns for one-sided external relations (see his slide)

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Conclusions

Rather than looking mainly at reification techniques from the modeling language point of view (Olivé 1999, Dalchour&Pirotte 2002, Halpin 2006), Nicola focuses on understanding the ontological nature of what may be relied...

... by systematically investigating why and how properties of relations hold

... and providing guidelines for reification choices according to the nature of their truth makers 

Crucial result: the recognition of qualities as weak truth makers

Further result: clarification of Guizzardi's distinction between formal and material relations, proposing a new classification of relations aimed at facilitating the analysis of actual modeling cases.

Proposed patterns may be easily incorporated in conceptual models based on DOLCE, UFO and BFO.

Ontobras 2019 - Keynote Speech: Conceptual Models as Ontological Contracts - By Giancarlo Guizzardi

Ontobras 2019 - Keynote Speech: Conceptual Models as Ontological Contracts
By Giancarlo Guizzardi
*My own comments are marked with an asterisk

“data are fragments of a theory of the real world, and data processing juggles representations of these fragments of theory...The issue is ontology, or the question of what exists.” (G.H. Mealy,  Another Look at Data, 1967)

Any artifact from which data can be extracted makes an ontological commitment, i.e. expresses  fragments of a theory.

Giancarlo explained the Twin Tower Case (available in the slides)

Regarding this case:

• There is no doubt about the brute reality. The issue is interpreting that part of reality according to a certain system of categories
• There are multiple views on reality that can conflict and unless we are fully aware of their distinctions, we cannot safely harmonize those views
• The is no experiment that can be done to settle these conflicts. It can only be resolve by conceptual clarification and meaning negotiation relying on a prioristic system of categories  

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Ontology as a Calculus of Content: a prior set of system categories as in foundational ontologies are necessary to provide an ontological analysis methodology to deal with the interpretation of reality.

Giancarlo explained the OntoUML taxonomy of Type using Mick Jagger as an example (see slides).
*OntoUML Wikipedia entry

OntoUML is a pattern language, since some of the concepts always appear together in a model. For example, a Role always specializes a Kind, so that the instances of the Role may take their identity principle from the Kind.

Giancarlo demonstrated the use of the Menthor Editor to create a model based on OntoUML patterns.

Some of the axiomatization comes for free with the OntoUML pattern.

Domain-specific axioms should be added to constrain the model, but also to express derived relation and the like.

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There is an OntoUML Benchmark: a repository of models in OntoUML.

Giancarlo described the work on Ontological Anti-patterns (see slides) and some results of an experiment conducted to find antipatterns in the OntoUML Benchmark.

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Finding patterns and anti-patterns in WikiData

Work in collaboration with João Paulo and Fred Brasileiro:  an experiment to find Multi-level Theory (MLT) patterns and anti-patterns in WikiData.

Example of problem found: 

Results of the experiment: 

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In the Q&A part, there was a lively discussion regarding the comparison of different Ontology languages.

Alloy is a very good ontology representation language, especially in terms of model simulation.

OntoUML vs. OWL

The languages are actually not competing at all, since one is dedicated to conceptual modeling and has no concern for computational tractability and the other is an ontology implementation language.

Giancarlo made a strong statement saying that there is no ontology in OWL although he acknowledges the value of such language in terms of providing a computationally tractable language and its benefits for web-based development.

Mathias highlighted that the issues of computationally tractability is a common issue not only restricted to ontology languages, and an important one.

Ontobras 2019 - Tutorial: Transforming clinical and clinical research data to ontology-driven linked data - By Mathias Brochhausen

Ontobras 2019 - Tutorial: Transforming clinical and clinical research data to ontology-driven linked data
By Mathias Brochhausen
(Slides available)
*My own comments are marked with an asterisk

Ontological reasoning may be used to assist in completeness in querying datasets. A real experiment showed an improvement in the retrieval of data regarding children living in a smoking household.

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Platform for imaging in Precision Medicine:
- efficiency and sustainability
- new tools for analysis
- improving ability to manage and analyze integrated datasets
- making clinical data available, both for text and image-based data

According to Mathias, the biggest problem he sees in data management is not related to how types are related, but the fact that many data managers do not account for the instances. He believes that OWL-based ontologies should not allow relations between types. The "arrows" should relate instances (or groups of instances).
*This is a bottom-up approach: from the data to the model
*When applying OntoUML, we actually take a top-down approach: from the model to the data. Perhaps because we often do not have the data to start with, and we are actually concentrating on understanding the domain.

João Paulo (JP): This discussion has also a lot to do with notation. Type relations are not a limitation for OWL Full.

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For heterogeneous bases, it is hard and costly to deal with mappings from all kinds of data formats. In his experience, using a triple store is the best way, if you need ontology-based reasoning over the data. He presented a case on the use of RDF-based data:

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Building a Pattern Repository for Instantiation of Patterns

- Patterns may help with reuse

- Which patterns should we store?
There are different ways to express the same knowledge. None of them is glaringly wrong. Some might be preferred over others for certain uses (e.g. for being quicker). If the patterns are all equally valid, I should prefer to use a patterns that other people are already using (that is what patterns are about, i.e. reuse, so that we do not all end up with different ontologies)

- They already have an ontology use pattern repository for which one may contribute and also use the existing patterns.

- These patterns differ from the ones provided at www.ontologydesignpatterns.org because while the latter aims at informing the design, the former is focused on informing how to instantiate the data.

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Representational Accuracy for Informed Consent Data

His group is involved with some case studies regarding the use of Biobanks' data. One thing that is very important is to acquire the consent of the owners of the medical material stored in these repositories.

- Related work: existing ontology on Inform Consent (Lin at al, 2013)

*full reference on slides

- For their specific case studies, they needed to specify rights and obligations, which was not contemplated in the work of (Lin et al, 2013).

- They used a Document Act Ontology (d-acts) to capture how rights and obligations are created.

*This work could evolve by using UFO-L

JP: the permission relation is an example of how type-type relation could be useful. 

Mathias  answered that it would indeed be easier to express it that way, but because they are limited by OWL-DL, they still take the approach of relating the instances instead of the types.

Gian: Do you see the need for a relator, i.e. an object that persists in time an is related to the event of giving consent?

Mathias answered that they are kind of "reductionist" in this sense, representing roles and events, but not relators. In the end of the discussion, he said he would need to think about the use of relators in his work.

One important disclamer that Mathias does is that not everything about consent is in the ontology. 

*This is in fact compliant with the OWL's open world assumption.

A glimpse of how they used d-act may be seen in the figures below:

Ontobras 2019 - Keynote Speech: Events and their context - By Nicola Guarino

Ontobras 2019 - Keynote Speech: Events and their context
By Nicola Guarino
*My own comments are marked with an asterisk


Objects (endurants) are involved in an event in different levels

E.g. John is thinking of Mary under the tree.
Focus: mental attitude (towards Mary) in John's mind
Maximal participant: John
Core participant: John's mind
Contextual participants: the three, the sun...
Virtual participant: Mary

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The philosophical debate on events: unifiers vs. multipliers

- unifiers - whatever happens in a spatiotemporal region. Thus, what Nicola calls scene is a unique event for unifiers

- multipliers - events are exemplification of properties (Kim); the exemplification of a change of x during t (Lombard)

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Nicola believes that different event names typically reflect different core aspects of what happened, so that event descriptions are not arbitrary

These core aspects can be captured by specifying, for each verb:
- its cognitive focus;
- the nature of its participants;
- what happens in the background.

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Qualitative Events

- We shall focus here on qualitative events. Existential and mereological events will not be considered.

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Qualities are subjects of events

- Aristotle (ref: Physics) says: in a process of change, we may distinguish three elements: That which changes, that in which it changes, and the actual subject of change.

- The proper subject of change are not the object (as suggested by Lombard), but qualities of the object.

Then, Nicola presents the concept of quality as defined in Dolce and UFO (foundational ontologies)

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Nicola then discussed the role of the event description's core verb in understanding the participation of objects in events.

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Event vs. Scene

Scene is viewed by some as a mix of objects and events. However, for Nicola, this is very problematic ontologically, especially because of having to account for objects as "part-of" events, which is strange.