Hello. Hello, everyone. My name is Ana Ibáñez and I am going to give you a brief introduction to the main concepts and the main contents of Unit 5 of the Chapter 5 of the coursebook on the Architecture of Words, Applications of Meaning Studies, which is the book we use in the degree, in the course Aplicaciones Semánticas de la Lengua Inglés, Adicionarios y Ontologías from the Degree of English Studies of UNED. So today we are going through the contents of Unit 5, which is entitled Meaning, Knowledge and Ontologies. OK, so what are the objectives of this session? First, we are going to see some differences between lexical products. We went through that already in previous units. Now we are going to compare specifically different lexical products to ontologies. So César. How are the terminologies ontologies? Here there is a link. Of course, you can download the PowerPoint. And then access the links, which now I will not go through. There is no time and it's not possible with this Blackboard to go through the links. But this is a link where it talks about the importance of ontologies, for instance, for multilingual contexts or for multilingualism. Although ontologies can be used in any area of life where we have to handle knowledge. We are going to see also various definitions of ontologies. So we are going to see how ontologies are approached from different perspectives. And we are also going to go through the different types of ontologies available nowadays, although they grow exponentially. So probably next year there will be other ontologies that have appeared. So for the introduction, as an introduction to this unit, we can just say that, well, let's start with the introduction to the unit. So the language means different things in different areas, for instance, in computer programming or in semantics or in linguistics. It has a different meaning than in everyday in an everyday context. The same happens with ontology. Ontology can be approached from a pro from the world of artificial intelligence for computer programming, or also it has a very big philosophical background already Aristotle and the philosopher, the Greek philosophers. In the ancient Greece, we're talking about ontology, ontologies. We are more focused on computer programming nowadays on artificial ontologies due to the. The fact that we are living in the digital era and in computer programming, a language is considered a kind of markup language. We have a lot of types of languages which have HTML, DML. We saw a bit of this in past uni. So I recommend you go through it again before continuing. And we also have in computer programming the concept of ontology, which is kind of the main concepts that are handled in an area of knowledge or in a database. So an ontology has to do. That's why it is. The word is highlighted. It has to do with concepts and. It is just as a reminder, a very simple idea that we are going to use to enter, to focus on this unit is the fact that concepts are transmitted by words. As humans. So we have to keep the what we have been going through in the previous units different. We have to keep in mind the important difference that exists between concepts and words, because this main difference is what will help us distinguish also ontologies from terminologies or from lexical, lexical or terminological approaches or ontological conceptual approaches. OK. And we are going to work on it. So now through very different approaches and definitions, some of them are complementary, others not so much. But in general, they tend to be complementary. One definition is knowledge networks. Ontologies are knowledge networks, so they are a collection of concepts that structure information and allow a user to view it. In this way, what is a structure? Structured information consists of organizing hierarchies where we have super-concepts and sub-concepts. So we make use of the idea of hyperonymy and hyponymy. A very interesting definition is quoted here, completely quoted from Heflin, who is the editor of OWL. OWL is a web ontology language, is one of the languages we use for the creation of ontologies, the main one. And he says an ontology defines the terms used to describe and represent an area of knowledge. Ontologists are used by people, databases, applications that need to share domain information. Ontologies include computer usable definitions of basic concepts in the domain and the relationships among them. They encode knowledge in the domain and also knowledge that spans domains. So in this way, they make that knowledge reusable. So basically, what is an ontology? An ontology is a way to handle knowledge, to structure knowledge into different domains, to encode it, to organize it. To establish relationships in order for knowledge to be retrievable, to be found, to be handled. We are going to go a bit more through that. Another approach to ontologies is to consider them databases or knowledge bases with different degrees of structure. Structure can be simple taxonomies, metadata schemes such as the Dublin Core or Yahoo hierarchy in the case of taxonomies, or they include also logical theories. So, a taxonomy and an ontology would include structures in terms of taxonomies, schemes, or logical relations. Another definition is a logic-based language. A logic-based language means that it uses meta-language, which we will go through later on. We will see some examples. In this type of language, it is important to distinguish among classes, properties, and relations. Heflin in 2004 also mentioned that ontologies figure prominently in the semantic web, so for the semantic web, which is the Web 3.0, the current web nowadays, ontologies are a very important part of it. Because they represent knowledge, they help us access the semantic of all documents. They help us structure knowledge, structure meanings. They make use of metadata, which labels this type of meaning. And so let's say that nowadays the semantic web needs ontologies to organize all the amount of information that is circulating constantly. Another definition is that the study, an ontology, the subject of an ontology is categories of things that exist or may exist in some domain. So we are going back again to the idea of category. The product of such a study called an ontology is a catalog of the types of things that are assumed to exist in a domain of interest D from the perspective of a person who uses a language L for the purpose of talking about X. I like this definition very much because it focuses on one type of ontology, which are domain-specific ontologies. So you can create an ontology of anything you want. Like when we were talking in Unit 4 about conceptual maps, an ontology is a kind of conceptual map, but much more developed in the sense that it's a step further because we don't have to see it visually as only the representation, but it's also everything that goes after the representation. So ontologies and concept maps are very much connected. We can take a domain, for instance, imagine I like bikes, types of bikes, the word of this would be our conceptual domain. I'm going to use a specific language to categorize all the knowledge that exists in that domain according to classes, relations, actions, instances, functions, etc. And I'm going to use this new language to talk about this specific topic in this domain, for instance, writing or types of engine, well, not engines, of wheels, for instance. Guarino, for instance, talks about logical axioms, so we have again the idea of logic, and we have designed to account for the intended meaning of a vocabulary, so it's a way of giving a logical language to meaning. And De Grotte, in 2013, already talked in a course in her space. It's a specialized course in terminology and terminography of ontologies. She was the lecturer of a course in 2013 about that in Ghent University. She defined ontologies as an agreed conceptualization, agreed is a conventionalized, it's a very important idea of a reality or of part of reality, depending on whether an ontology is a domain-specific or general ontology. And it is based on classes. Classes, relations, functions, actions, instances. And ontology goes further than a thesaurus because it can comprise, usually comprises a thesaurus, which in turn comprises a taxonomy, so a hierarchy classification of a part of reality using one relation type. Thank you. In ontologies, we have three or four relation types. We have functions, different functions. These logical actions include different types of relations in a taxonomy. We only have one relation type, which is a class of a taxonomy has this type of relation and ontology can have more types of relations. And here you have from Stanford University. Why do I include this link? Because I would like you to visit it. Stanford University is the one that has designed Protege. Protege is a program to design ontologies. So this is the most used program to create an ontology nowadays. And indeed, in their Web page they have with a very simple HTML language, very simple Web pages. You have what you have a web page. What I have copy, paste it here from this link. But much more information about how to create an ontology, why we need an ontology, the structure of an ontology. So I really recommend this link. Basically now, I just wanted to mention that their definition, because we are now focusing on this, of an ontology. They say that an ontology defines a common voice. It defines a vocabulary for researchers who need to share information in a domain. So it is, as they mentioned, a conventionalized or an agreed language and structure. It is important that they mention that it includes machine interpretable definitions. So that's why we need this logic language or this metadata to make it understandable for machines. And it includes these concepts, basic concepts and the relations. The reasons to develop an ontology, to share common understanding, to reuse knowledge, to make domain assumptions explicit, to, let's say, to agree on what we consider from a part of the domain or not, to separate domain knowledge from operational knowledge, to analyze domain knowledge. All these ideas sound very abstract, but let's put a practical application to it. Let's say, for instance, we are using it for translation. One of the areas where ontology is used, apart from the main area, which is the semantic web, translation. Machine translation is another area that really needs ontologies. If we define a domain or the domain of a specific area of knowledge, we are going to be able to create correspondences between languages much more easily. And we are going to make it interpretable for a machine. It can also be applied, for instance, to voice recognition programs. This city, this Alexandra, or what? Is the name Alexandra? I don't remember. Sorry. But, well, these robots or bots that reply to us, they do it thanks to this type of ontologies that have been designed to interpret, to obtain the data. Thank you. From the data we are providing, they have given them specific definitions that can be interpreted by the machines so they can recognize the information we are providing. And thanks to this, they can also give a certain output. So that's, for instance, another important application of ontologies. All in all, all definitions include, if you have paid attention to it, classics. So the general things, the relationships and the properties or attributes that these things have. So the things that exist, the relationships that exist among these things and the properties these things have. This is a link that I cannot click on now, but as I said, I suggest you click on and investigate a bit. It's for how to create your own ontology. And. It's the guide for using Protegi from Stanford University. Now we are going to continue with point four, where we are going to see the differences between databases, terminologies and ontologies. We are going to go through a main through a very important example, which is WordNet. Apart from Protegi, to create ontologies, a very interesting lexical database of English lexical database is the set of It's another different thing from an ontology, but it's interesting to see the differences. OK, this is a database, but it is a lexical database. What happens with the lexical database as WordNet? WordNet was created in Princeton already a decade ago or almost two decades ago, but it keeps on being developed and it is used for many scholars all around the world because they have it freely available on the Internet. They have old versions and the new version. The new version was released, I think, already only a few months ago. What is based on? Well, WordNet is based on lexical items, nouns, verbs, adjectives and adverbs and then function words and they are grouped into sets of cognitive synonyms. So they play the basic idea of these lexical databases, the idea of synsets. They express different concepts. But first of all, they take lexical items and they organize them into groups of synonyms according to the concept they express. So these synsets, it's a specific term they use to refer to these, are interlinked by means of conceptual, semantic and lexical relationships. So why is this? Why is this lexical database different from WordNet? Which is WordNet, sorry, different from Thesaurus? It is different because it groups, Thesaurus groups based on the meaning. Both of them were grouped, sorry, both of them grouped words together based on their meaning, but there are important distinctions. Because in Ethesaurus, the word forms are grouped according to their meaning. So, words that are found in close proximity to one another are disambiguated. So, sorry, in WordNet, they are not just word forms. They play with the idea of disambiguation because, as I said, words that are found in close proximity to one another are semantically disambiguated. So, the semantic relations among words are the most important. In Ethesaurus, words are grouped together just following one pattern, which is mutual. Meaning similarity. But this is the only pattern, the relation that is used. Meaning similarity. In WordNet, it is not only word forms that have similarities, but also there is a whole semantic network created among them. I'm going to go a bit deeper into this. As I said, the main relationship. The main relationship in WordNet is synonymy. Words that denote the same concept are interchangeable in many contexts, so they are grouped together into unordered sets, which are syn-sets. And these words establish a number of conceptual relations, and each scene set, which groups a number of words, contains a brief definition, which is called gloss, and in most cases, one or more short sentences that illustrate the use of scene sets for members. So, this scene set is a group of concepts that are related, both all synonyms, there is a common definition for them, and also a way of using them. Words can form several distinct meanings, and they can become two different scene sets. So, the form, together with the concept, is consistent. It constitutes a pair, which is unique in the word line, let's say. In Ethesaurus, words are together, but they don't go to the last step, which is disambiguation. Because you can group, for instance, a conceptual, let's go to a specific example in Ethesaurus. We can have, for instance, I don't know, hugging. And then we have different words that denote the idea of hugging. This same idea would also apply for WordNet, but apart from this, all the words. that can be this and be created because they also have a different meaning will be organized also in another different season where they have a specific meaning for this insert okay this would be a bit the main difference here is just the web then the screenshot of WordNet that you can see they have publications there is here an area where you can download the versions it is much easier with Windows with Mac they have a new version that today I couldn't download so I have used always the older version for the new version I think they they need to implement some other but probably with within a few days soon. it will be also available and they give a lot of information about their own project why it is useful etc so this would be a lexical database then we go to terminologies terminologies are different from lexical databases or from databases because they don't first of all remember we were talking in previous units about the semaceological approach and then onomaceological approach depending on whether we approach the lexicon through first focusing on the term on the form or through first focusing on the concept you In WordNet, this lexical database, we first focus on the concept. And through this concept, where we create these insets, we include the different terms. In a terminology, it is different because we first look for the terms, we organize them, and then we see what they mean. And we locate them in different specialized conceptual domains. The difference between a dictionary and a terminology database, a terminological database, as we saw before already, this is just reviewing this, is that dictionaries have to do with general language, let's say. And we have also, as we see here, synonyms that are usually scattered throughout the dictionary. And polysemous words and homonyms are grouped together. In dictionaries, in terminologies, they are restricted to specific domains. And the terms that are homonyms are not only synonyms. Synonyms will also be put together according to the domain they belong to. But the most important difference is that terminologies have to do with specific areas of language. So they are more for language for specific. For instance, the terminology database for mechanics or a terminology of translation, translation terminology. or medicine terminology. Lexicology had to do with the study of words in general then, and the result of lexicological studies will give us lexical databases or dictionaries, whereas terminology has to do with the study of specialized language, and the result will give us terminological databases. We saw also a few databases, very famous databases and very widely used. The European Commission has developed their own terminological databases. This is very important for translation studies, as you know, especially in the European Union when we have so many official languages for communication purposes, for political relationships, for policy making, and so on and so on. Terminologies then are more sense-based, that's why it is highlighted. The terms they contain map an area of specialized knowledge, and as I said the relationships between the concepts which the term represents are the main organizing principle of the terminology. In dictionaries words are organized first of all alphabetically. Of course relationships are important, but the most important is the content. We saw this before, this is just a review as I said. In dictionaries, each item, and in lexicology, each item is observed individually. And for each item, we work with the definition, then the spelling, the etymology, etc., etc. Whereas in terminologies or in lexical database, we are studying units in groups. We group together concepts according to their conceptual domain, their meaning, their uses, etc. So it's not individual work, it's more group work. We were studying... I was saying before, what are the applications of ontologies? Well, Nirenburg and Raskin mentioned a few. There could be many more. But as I said, machine translation is one of the biggest uses of ontologies. Information extraction for the semantic web, for instance. Question and answering, what I was saying about Siri or Alexandra, I don't know if she's called Alexandra. Text summarization. Answering. General human-computer dialogue systems are the combination of all of them. These are... So this is all, in fact, the same types of applications that computational dictionaries offer. So first of all, what is the difference then between dictionaries and ontologies? We set the approach towards the analysis of language and concepts. The approach is conceptual, not from the word form, but from the concept. This is already different. Also, it is different the type of language they use. They are more into the logical languages, into the metadata, etc. Applications that are based on ontological approach to meaning can all also have to undergo not only what dictionaries do, computational dictionaries, but other stages, such as tokenization, parsing. And if all these stages succeed, then we generate the meaning of a text or what is called text meaning representation. So. Here we have the input towards specialized processing. As I said, ontologies go a step further or they are more abstract, obviously, because they continue in their stages of development. And the fact that they use logic language, these different organization of language accordingly. So, we are going to the relations and the properties, etc. Hello, Maria. Thank you. Some examples in machine translation, text meaning representation needs to be translated into a natural language different from the one in which the input was supplied. So the program that does this task is usually called text generation. This is in machine translation. And in information extraction, text meaning representations are used also by special rules as sources of fillers of the user's query. The question answering processor must first understand exactly what the user wants the system to do, then find the necessary information, and then be able to generate a well-formed answer. So we need this. Let's say that we need like a transitional language that goes from the logic language we have created with all these metadata relations properties to natural language, to our natural language. All this is done through different systems, which is this tagging, this parsing, this meta-language, this logical language that has different codes. I'm going to give an example at the end. Okay. Shaly and Safferet also, talking about ontologies and language, they say that ontologies are useful to compare different languages. And why? Because for an ontology, in order for an ontology to be reliable, let's say, and also consistent and sustainable in time, we need it to be cross-cultural. And we need to rely on concepts that are the same across human minds, cultures and languages. We know that culture is very idiosyncratic. We are idiosyncratic. We have different cultures and we need to go. They propose this and I agree with this, but this doesn't mean that in reality there are domain-specific ontologies, that there are not, because there are, or ontologies that are very language-specific, not language-specific, but culture-specific. But this proposal, I think it is interesting. To make ontologies usable and reusable for cross-linguistically, and make them more language-independent. How do we do this? Finding universal concepts in our languages, concepts that are cross-cultural, let's say. For instance, the idea of mother, the idea of father. I don't know if there are for this. We would need anthropologists. We would need a social linguist. Psycholinguists, et cetera, ethnologists that help us identify these universal concepts so that we can create a language-independent ontology and a culture-independent ontology. Talking about the concepts and ontological relationships. The position a concept holds within a given ontology is determined by ontological relations. This is just a review of what we just said. In an ontology, we need concepts and we also need relations. And these relations are organised in terms of taxonomies and metonymic relations. So, how we organise concepts? What are these types of relations? A type of, class of, pertaining to a certain class of, or part of another type of relation. And sub-concepts or general concepts, more specific concepts. Like hyponymic and hyperonymic relations. Apart from this, we also need, as we said before, attributes to these main entities that for part constitute an ontology. And an interesting authors that are mentioned in the book is Dismetzinger and Gallese, who went as far as comparing an ontology to our books. Their idea is very ambitious, because for them an ontology should represent how we view the world. This is more... Let's say a theory, and in practice, of course, this is a very ambitious achievement. It's very ambitious, let's say. But I think it's a very interesting approach to consider ontologies a way of interpreting the world and to even they found empirical evidence that the brain models movements and action goals in terms of these multimodal representations of organism, objects, and relations. So their idea was to analyze how our brain works and then to transfer this to ontologies. And if this can be achieved, it has been achieved in some instances, this would be the best proposal. And the best idea to create ontologies that are, as we said, cross-linguistic or cross-cultural and sustainable in time. What is the most important challenge for ontologies? Ambiguity. Ambiguity is what distinguishes natural languages and ontologies. For instance, the mapping of one lexical entry into two separate concepts. We have wall. We can have an inside wall in English or an outside wall. This is a polysemous word in English, but in Spanish, we already have two different terms for the same term that exists in English, which is pared and tapia. So. What happens is that in an ontology, these polysemous terms, such as world, will be part of a different section, as I was saying, in the ontology or in the building of the concepts. Because, as we said, ontologies are organized around domains and concepts, not around terms, as could happen in a dictionary or in a thesaurus. Finally, we could say that language is used by people's ontologies and both as constructed for computers or as a philosophical discipline, and they are made ad hoc. Let's say that, in conclusion, what the book means by this, what Margarita Godet, the author of this chapter, meant by this is that both ontologies, either from a computer or from a computer, are made ad hoc. Or from a philosophical perspective, are made by people, for the people, and according to the concepts that we have. But this proposal of creating ontologies that are cross-linguistic and cross-conceptual is, for me, a very interesting one, although this is a subjective view. Because, in fact, if ontologies are based on concepts, and the language is a conceptual phenomenon, and culture is a conceptual phenomenon, it can be very challenging. Because this could be a very, let's say, how could we say, it could reduce reality too much if we only focus on universal concepts. But... In the end, what we have now a days in reality is that there is a big emergence of ontologies of all kinds. Sometimes it is very difficult even to catch up and to follow all these new ontologies that are created. And I wonder whether sometimes as a linguist and as an academic of this, I wonder whether it would be more economical to try to focus first on all the things that we have in common conceptually to create a very simple ontology that can be just usable and used by all speakers of all languages. Maybe this is very ambitious also because here we are going to talk about metalanguage. Even if we try to separate ontologies, from language because we are they are supposed to be language independent. We need the metalanguage. What happens with the metalanguage, which is it is a bit as we say in Spanish, el pez que se muerde la cola. And as you have seen in this degree, there are many types of metalanguages, but a metalanguage makes use of language. In this case, for instance, we have the example of the corel conceptual representation language, which is an ontology created by language. By our chancellor, Ricardo Mairal and Periñan Pascual and others in a big project they started already more than a decade ago. Where they wanted to create the language of all concepts. But of course, what do they use in their metalanguage? English words. So it is language independent, but they use a lingua franca, which is English. The ambitious idea of using a language that is not a language is really... I don't know if it is possible, let's say. It is very interesting this language. You can investigate a bit more about this. They are based on thematic frames as FrameNet, which is a very interesting also lexical database. For instance, answer. The concept of answering is represented like this and it has a thematic frame. In this case, it could be X1 a human, which is the theme, X2 answers to a reference, which is another human. This would be X3. This would be the topic and this would be the reference and the goal, the meaning postulate, etc. Well, this is the whole thematic frame of answer. The answer would be the event and belongs to a higher frame of the metaconcept communication, to which the metaconceptual unit is assigned a prototypical thematic frame. So this is very ambitious, but it worked in a way. So the thematic frame of communicative situations has a metaconcept, which is communication. And this would be just this metaconcept theme. This thematic frame derives from the general theme as well as the meaning postulate. And this meaning posterior could be someone, x1 says something, x2 to somebody, x3 related to equation x4 that x3 said to x1. So imagine how complicated it can be. But if we manage to implement this to a computer program and make it understandable for a computer, then we succeed. But as you see, this metalanguage is not completely language independent because it is making use of English. Is this possible to avoid? It is hard, let's say. We can see also that they use logic symbols such as plus, the hashtag, the x, the numbers, like as in logics or in generative grammar or in functional grammar. So logic. Logic, of course, is very, very necessary for this type of language. And I'm here just going to give you an example of an ontology. This is just the notes we were taking in a meeting because I have a PhD student who is developing an ontology for educational resources in order to later on being able to be able to implement it to search engines that would give advice and recommendations according to the person's profile on different degrees. Or courses around the world. So we were having a meeting with my PhD student and Omar who is working for. A. For a project from the Internet, I will explain later, from the computer science department with Salvador Ross, who has a very interesting project. They are designing an ontology for poetry and he's the developer of this ontology. So we had a meeting with Omar and my PhD student and he was teaching us how to design an ontology. And here you can see a bit of a sample because he gave us a really interesting masterclass on how we start developing an ontology. First, we have to have an object. It is in Spanish. The PhD is in Spanish. Objetivo de alto nivel. ¿Cuál es el objetivo? Facilitar configuración de experiencias formativas. Here we include our own objective, which is what my PhD student was doing, our PhD. Concentración. Paso de uso. For instance, objetivos de alto nivel relacionados. Uno, personalización del proceso de aprendizaje. Dos, estudio y evaluación de los recursos de aprendizaje. ¿Qué necesito? ¿Qué preguntas de competencia formulo? Respecto de las personas. So this is basically her main objectives in the thesis. In the thesis. With just HTML. In the HTML language, what he does first is to establish relations. You see? This is the first step. With O1, ZU1, ZU2, RT1, PC1. ¿Qué necesitas? So, that's how it starts an ontology, creating concepts, domains and relations and attributes. And this is I wanted to show you just as an example. And finally, we're going to go through types of ontologies. We have upper ontologies, here you have some examples which appear also in the book and domain-specific ontologies with very specific concepts, such as the one I just showed you that is being developed by our PhD. The principles in all of them are language independence, but as I said, this is quite of a challenge. They have to be well formed according to axioms and a good axiomatic specification. They have to have a similarity principle and opposition principle. For instance, a similarity principle means a child must share the meaning of a parent, so they all have to share some meanings, of course, and agreed meanings. A specificity principle would say a child must differ from his parent in a distinctive way, and an opposition principle is that the concept must be distinguishable from his siblings and the distinction between each pair of siblings must be represented in order for the disambiguation to take place. In Artificial Intelligence, they focus on the computational reasoning about using ontological knowledge on the computationally intelligent acquisition and revision of new knowledge. This would be the use of ontologies. And the principles ontologists have to have in artificial intelligence. So they have to include computational reasoning. They have to be able to revise new knowledge and they have to be computationally intelligent. That's why we need also computer developers for the development of ontologies. And that's why one of these big projects that is being carried out in Spain is being carried out in the computer science department of UNED, not only in the linguistics department. In fact, this project belongs to the computer department. So for an ontology, a lot of computer engineers are required. Knowledge basis. Finally, a knowledge base. Why is it different from an ontology based ontology? Because they are very similar, but an ontology is a much broader term. It can include the database, but it also, as we have seen by now, includes a lot of much, much more types of information. Knowledge bases collect facts, rules. They have inference procedures, how to make use of these rules, but the organization, the language used, the taxonomies, the meronymic relations, the metalanguage all this is going a step further than a knowledge base finally these are some of the links you have also in the book for language tools and here I have included some other links which are really really recommended this one is just to see what is an ontology, what an ontology is, you have three links about that and here there is a link to a very interesting paper on an introduction to ontologies and ontology engineering these are two PDFs that I recommend and here this is the screenshot and the link to the department of UNE that is designing this poetry ontology and it could it is quite interesting for you to just go through it and see how it is being developed it is called as you see poetry lab apps they have an application you have here information about the team and this is part also of the the laboratory of digital humanities of UNE this professor Salvador Ros belongs to this laboratory And this is one of the projects they have. As you can see here, it is called Poetry Standardization and Linked Open Data. So as you can see, this is also used for open data, for linking open data ontologies. So this was all by now. If you have any doubts, use the forum for Unit 5. What I would like to tell you basically also is that this last chapter is quite abstract. It has been written in a very technical language, so don't be afraid and don't be very scared. I know it is very hard to understand. The only thing I could do is to recommend you go through... ...through some of the links I gave you, apart from just understanding that, of course, this is a very complex topic that is part of specialized technologists, computer technologists, as I say, together with linguists. So it is really something for postgraduates or even PhDs. And at this level or in a degree, the main idea for me was to transmit... ...to you the difference between an ontology, even if you, when you go to an ontology, you don't really understand how it fully works, but at least to be able for you to distinguish what an ontology would be compared to a thesaurus, a dictionary, a terminological database. a conceptual map. Ontologies are, let's say, the most complex developments of nowadays of knowledge, of handling, for handling knowledge and they are behind of, behind machine translation, the semantic web, data retrieval, as you can see. There are many, many ways of using them and they are very, very specialized and there are many, many, many ontologies all over the world. There you see, I will try to share with you in the course an article, not for you to read it fully because you would spend a whole semester on it, but it's an article where some scientists are doing a revision of all the, all the available ontologies that exist nowadays and that have been done in the course of history and I can assure you there are projects all over the world, very, very interesting projects, very complex. So the idea is just to have a small picture of what is being done and to try to make some sense of it to understand that ontologies are more based on relations on their abstract concepts. On logics that they use, make use of meta languages, that they are based on conceptual domains and that they are an attempt to be able to organize knowledge. to structure knowledge and to handle knowledge in the digital era where we are now, where we need to especially develop tools to organize all this knowledge around. And that was it. So thanks for watching by now.