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Pas une pipe

This blog post offers a simple guide to the landscape of signification in language. We’ll begin by distinguishing the numerous elements that construct meaning. We’ll start by having a look at signs, and how they are everywhere in communication between living beings and how a sign is different from a symbol for instance. A symbol is a special kind of sign unique to humans, that folds into a signifier (a sound, an image, etc.) and a signified (a category or a concept). We’ll learn that the relationship between a signifier and a signified is conventional. A bit further, I’ll explain the workings of language, our most powerful symbolic system. I will review successively what grammar is: the recursive construction of sense units; semantics: the relations between these units; and pragmatics: the relations between speech, reference and social context. I’ll end this chapter by recalling some of the problems in fields of natural language processing (NLP).

Sign, symbol, language

Sign

Meaning involves at least three actors playing distinct roles. A sign (1) is a clue, a trace, an image, a message or a symbol (2) that means something (3) for someone.

A sign may be an entity or an event. What makes it a sign is not its intrinsic properties but the role it plays in meaning. For example, an individual can be the subject (thing) of a conversation, the interpreter of a conversation (being) or he can be a clue in an investigation (sign).

A thing, designated by a sign, is often called the object or referent, and – again –what makes it a referent is not its intrinsic properties but the role it plays in the triadic relation.

A being is often called the subject or the interpreter. It may be a human being, a group, an animal, a machine or whatever entity or process endowed with self-reference (by distinguishing self from the environment) and interpretation. The interpreter always takes the context into account when it interprets a sign. For example, a puppy (being) understands that a bite (sign) from its playful sibling is part of a game (thing) and may not be a real threat in the context.

Generally speaking, communication and signs exist for any living organisms. Cells can recognize concentrations of poison or food from afar, plants use their flowers to trick insects and birds into their reproductive processes. Animals – organisms with brains or nervous systems – practice complex semiotic games that include camouflage, dance and mimicries. They acknowledge, interpret and emit signs constantly. Their cognition is complex: the sensorimotor cycle involves categorization, feeling, and environmental mapping. They learn from experience, solve problems, communicate and social species manifest collective intelligence. All these cognitive properties imply the emission and interpretation of signs. When a wolf growls, no need to add a long discourse, a clear message is sent to its adversary.

Symbol

A symbol is a sign divided into two parts: the signifier and the signified. The signified (virtual) is a general category, or an abstract class, and the signifier (actual) is a tangible phenomenon that represents the signified. A signifier may be a sound, a black mark on white paper, a trace or a gesture. For example, let’s take the word “tree” as a symbol. It is made of: 1) a signifier sound voicing the word “tree”, and 2) a signified concept that means it is part of the family of perennial plants with roots, trunk, branches, and leaves. The relationship between the signifier and the signified is conventional and depends on which symbolic system the symbol belongs to (in this case, the English language). What we mean by conventional is that in most cases, there is no analogy or causal connection between the sound and the concept: for example, between the sound “crocodile” and the actual crocodile species. We use different signifiers to indicate the same signified in different languages. Furthermore, the concepts symbolized by languages depend on the environment and culture of their speakers.

The signified of the sound “tree” is ruled by the English language and not left to the choice of the interpreter. However, it is in the context of a speech act that the interlocutor understands the referent of the word: is it a syntactic tree, a palm tree, a Christmas tree…? Let’s remember this important distinction: the signified is determined by the language but the referent depends on the context.

Language

A language is a general symbolic system that allows humans to think reflexively, ask questions, tell stories, dialogue and engage in complex social interactions. English, French, Spanish, Arabic, Russian, or Mandarin are all natural languages. Each one of us is biologically equipped to speak and recognize languages. Our linguistic ability is natural, genetic, universal and embedded in our brain. By contrast, any language (like English, French, etc.) is based on a social, conventional and cultural environment; it is multiple, evolving and hybridizing. Languages mix and change according to the transformations of demographic, technological, economic, social and political contexts.

Our natural linguistic abilities multiply our cognitive faculties. They empower us with reflexive thinking, making it easy for us to learn and remember, to plan in the long-term and to coordinate large-scale endeavors. Language is also the basis for knowledge transmission between generations. Animals can’t understand, grasp or use linguistic symbols to their full extent, only humans can. Even the best-trained animals can’t evaluate if a story is false or exaggerated. Koko the famous gorilla will never ask you for an appointment for the first Tuesday of next month, nor will it communicate to you where its grandfather was born. In animal cognition, the categories that organize perception and action are enacted by neural networks. In human cognition, these categories may become explicit once symbolized and move to the forefront of our awareness. Ideas become objects of reflection. With human language comes arithmetic, art, religion, politics, economy, and technology. Compared to other social animal species, human collective intelligence is most powerful and creative when it is supported and augmented by its linguistic abilities. Therefore, when working in artificial intelligence or cognitive computing, it would be paramount to understand and model the functioning of neurons and neurotransmitters common to all animals, as well as the structure and organization of language, unique to our species.

I will now describe briefly how we shape meaning through language. Firstly, we will review what the grammatical units are (words, sentences, etc.). Secondly, we will explore the semantic networks between these units, and thirdly, what are the pragmatic interactions between language and extralinguistic realities.

Grammatical units

A natural language is made of recursively nested units: a phoneme which is an elementary sound, a word, a chain of phonemes, a syntagm, a chain of words and a text, a chain of syntagms. A language has a finite dictionary of words and syntactic rules for the construction of texts. With its dictionary and set of syntactic rules, a language offers its users the possibility to generate – and understand – an infinity of texts.

Phonemes

Humans beings can’t pronounce or recognize several phonemes simultaneously. They can only pronounce one sound at a time. So languages have to obey the constraint of sequentiality. A speech is a chain of phonemes with an acoustic punctuation reflecting its grammatical organization.

Phonemes are meaningless sounds without signification1 and generally divided into consonants and vowels. Some languages also have “click” sounding consonants (in Eastern and Southern Africa) and others (in Chinese Mandarin) use different tones on their vowels. Despite the great diversity of sounds used to pronounce human languages, the number of conventional sounds in a language is limited: the order of magnitude is between thirty and one hundred.

Words

The first symbolic grammatical unit is the word, a signifier with a signified. By word, I mean an atomic unit of meaning. For example, “small” contains one unit of meaning. But “smallest” contains two: “small” (meaning tiny) and “est” (a superlative suffix used at the end of a word indicating the most).

Languages contain nouns depicting structures or entities, and verbs describing actions, events, and processes. Depending on the language, there are other types of words like adjectives, adverbs, prepositions or sense units that orient grammatical functions, such as gender, number, grammatical person, tense and cases.

Now let’s see how many words does a language hold? It depends. The largest English dictionary counts 200,000 words, Latin has 50,000 words, Chinese 30,000 characters and biblical Hebrew amounts to 6,000 words. The French classical author Jean Racine was able to evoke the whole range of human passions and emotions by using only 3,700 words in 13 plays. Most linguists think that whatever the language is, an educated, refined speaker masters about 10,000 words in his or her lifetime.

Sentences

Note that a word alone cannot be true or false. Its signifier points to its signified (an abstract category) and not to a state of things. It is only when a sentence is spoken in a context describing a reality – a sentence with a referent – that it can be true or false.

A syntagm (a topic, sentence, and super-sentence) is a sequence of words organized by grammatical relationships. When we utter a syntagm, we leave behind the abstract dictionary of a language to enter the concrete world of speech acts in contexts. We can distinguish three sub-levels of complexity in a syntagm: the topic, the sentence, and the super-sentence. Firstly, a topic is a super-word that designates a subject, a matter, an object or a process that cannot be described by just a single word, i.e., “history of linguistics”, “smartphone” or “tourism in Canada”. Different languages have diverse rules for building topics like joining the root of a word with a grammatical case (in Latin), or agglutination of words (in German or Turkish). By relating several topics together a sentence brings to mind an event, an action or a fact, i.e., “I bought her a smartphone for her twentieth birthday”. A sentence can be verbal like in the previous example, or nominal like “the leather seat of my father’s car”. Finally, a super-sentence evokes a network of relations between facts or events, like in a theory or a narrative. The relationships between sentences can be temporal (after), spatial (behind), causal (because), logical (therefore) or underline contrasts (but, despite…), and so on.

Texts

The highest grammatical unit is a text: a punctuated sequence of syntagms. The signification of a text comes from the application of grammatical rules by combining its signifieds. The text also has a referent inferred from its temporal, spatial and social context.

In order to construct a mental model of a referent, a reader can’t help but imagine a general intention of meaning behind a text, even when it is produced by a computer program, for instance.

Semantic relationships

When we hear a speech, we are actually transforming a chain of sounds into a semantic network, and from this network, we infer a new mental model of a situation. Conversely, we are able to transform a mental model into the corresponding semantic network and then from this network, back into a sequence of phonemes. Semantics is the back and forth translation between chains of phonemes and semantic networks. Semantic networks themselves are multi-layered and can be broken down into three levels: paradigmatic, syntagmatic and textual.

hierarchy-units-any-language

Figure: Hierarchy of grammatical units and semantic relations

Paradigmatic relationships

In linguistics, a paradigm is a set of semantic relations between words of the same language. They may be etymological, taxonomical relations, oppositions or differences. These relations may be the inflectional forms of a word, like “one apple” and “two apples”. Languages may comprise paradigms to indicate verb tenses (past, present, future) or mode (active, passive). For example, the paradigm for “go” is “go, went, gone”. The notion of paradigm also indicates a set of words which cover a particular functional or thematic area. For instance, most languages include paradigms for economic actions (buy, sell, lend, repay…), or colors (red, blue, yellow…). A speaker may transform a sentence by replacing one word from a paradigm by another from the same paradigm and get a sentence that still makes sense. In the sentence “I bought a car”, you could easily replace “bought” by “sold” because “buy” and “sell” are part of the same paradigm: they have some meaning in common. But in that sentence, you can’t replace “bought” by “yellow” for instance. Two words from the same paradigm may be opposites (if you are buying, you are not selling) but still related (buying and selling can be interchangeable).

Words can also be related when they are in taxonomic relation, like “horse” and “animal”. The English dictionary describes a horse as a particular case of animal. Some words come from ancient words (etymology) or are composed of several words: for example, the word metalanguage is built from “meta” (beyond, in ancient Greek) and “language”.

In general, the conceptual relationships between words from a dictionary may be qualified as paradigmatic.

Syntagmatic relationships

By contrast, syntagmatic relations describe the grammatical connections between words in the same sentence. In the two following sentences: “The gazelle smells the presence of the lion” and “The lion smells the presence of the gazelle”, the set of words are identical but the words “gazelle” and “lion” do not share the same grammatical role. Since those words are inversed in the syntagmatic structure, the sentences have distinct meanings.

Textual relationships

At the text level, which includes several syntagms, we find semantic relations like anaphoras and isotopies. Let’s consider the super-sentence: “If a man has talent and can’t use it, he’s failed.” (Thomas Wolfe). In this quotation “it” is an anaphora for “talent” and “he”, an anaphora for “a man”. When reading a pronoun (it, he), we resolve the anaphora when we know which noun – mentioned in a previous or following sentence – it is referring to. On the other hand, isotopies are recurrences of themes that weave the unity of a text: the identity of heroes (characters), genres (love stories or historical novels), settings, etc. The notion of isotopy also encompasses repetitions that help the listener understand a text.

Pragmatic interactions

Pragmatics weave the triadic relation between signs (symbols, speeches or texts), beings (interpreters, people or interlocutors) and things (referents, objects, reality, extra-textual context). On the pragmatic level of communication, speeches point to – and act upon – a social context. A speech act functions as a move in a game played by its speaker. So, distinct from semantic meaning, that we have analyzed in a previous section, pragmatic meaning would address questions like: what kind of act (an advice, a promise, a blame, a condemnation, etc.) is carried by a speech? Is a speech spoken in a play on a stage or in a real tribunal? The pragmatic meaning of a speech also relates to the actual effects of its utterance, effects that are not always known at the moment of the enunciation. For example: “Did I convince you? Have you kept your word?”. The sense of a speech can only be understood after its utterance and future events can always modify it.

A speech act is highly dependent on cultural conventions, on the identity of speakers and attendees, time and place, etc. By proclaiming: “The session is open”, I am not just announcing that an official meeting is about to start, I am actually opening the session. But I have to be someone relevant or important like the president of that assembly to do so. If I am a janitor and I say: “The session is open”, the act is not performed because I don’t have any legitimacy to open the session.

If an utterance is descriptive, it’s either true or false. In other cases, if an utterance does something instead of describing a state of things, it has a pragmatic force instead of a truth value.

Resolving ambiguities

We have just reviewed the different layers of grammatical, semantic and pragmatic complexity to better understand the meaning of a text. Now, we are going to examine the ambiguities that may arise during the reading or listening of a text in a natural language.

Semantic ambiguities

How do we go from to the sound of a chain of phonemes to the understanding of a text? From a sequence of sounds, we build a multi-layered (paradigmatic, syntagmatic and textual) semantic network. When weaving the paradigmatic layer, we answer questions like: “What is this word? To what paradigm does it belong? Which one of its meanings should I consider?”. Then, we connect words together by answering: “What are the syntagmatic relations between the words in that sentence?”. Finally, we comprehend the text by recognizing the anaphoras and isotopies that connect its sentences. Our understanding of a text is based on this three-layered network of sense units.

Furthermore, ambiguities or uncertainties of meaning in languages can happen on all three levels and can multiply their effects. In the case of homophony, the same sound can point to different words like in “ate” and “eight”. And sometimes, the same word may convey several distinct meanings like in “mole”: (1) a shortsighted mouse-like animal digging underground galleries, (2) an undercover spy, or (3) a pigmented spot or mark on the skin. In the case of synonymy, the same meaning can apply to distinct words like “tiny” and “small”. Amphibologies refer to syntagmatic ambiguities as in: “Mary saw a woman on the mountain with a telescope.” Who is on the mountain? Moreover, who has the telescope? Mary or the woman? On a higher level of complexity, textual relations can be even more ambiguous than paradigmatic and syntagmatic ones because rules for anaphoras and isotopies are loosely defined.

Resolving semantic ambiguities in pragmatic contexts

Human beings don’t always correctly resolve all the semantic ambiguities of a speech, but when they do, it is often because they take into account the pragmatic (or extra-textual) context that is generally implicit. It’s in a context, that deictic symbols like: here, you, me, that one over there, or next Tuesday, take their full meaning. Let’s add that, comparing a text in hand with the author’s corpus, genre, historical period, helps to better discern the meaning of a text. But some pragmatic aspects of a text may remain unknown. Ambiguities can stem from many causes: the precise referents of a speech, the uncertainty of the speaker’s social interactions, the ambivalence or concealment of the speaker’s intentions, and of course not knowing in advance the effects of an utterance.

Problems in natural language processing

Computer programs can’t understand or translate texts with dictionaries and grammars alone. They can’t engage in the pragmatic context of speeches like human beings do to disambiguate texts unless this context is made explicit. Understanding a text implies building and comparing complex and dynamic mental models of text and context.

On the other hand, natural language processing (a sub-discipline of artificial intelligence) compensates for the irregularity of natural languages by using a lot of statistical calculations and deep learning algorithms that have been trained on huge corpora. Depending on its training set, an algorithm can interpret a text by choosing the most probable semantic network amongst those compatible within a chain of phonemes. Imperatively, the results have to be validated and improved by human reviewers.

 

I was happily surprised to be chosen as an “IBM influencer” and invited to the innovation and disruption Forum organized in Toronto the 16th of November to celebrate the 100th anniversary of IBM in Canada. With a handful of other people, I had the privilege to meet with Bryson Koehler the CTO of the IBM Cloud and Watson (Watson is the name given to IBM’s artificial intelligence). That meeting was of great interest to me: I learned a lot about the current state of cloud computing and artificial intelligence.

Robot

Image: Demonstration of a robot at the IBM innovation and disruption forum in Toronto

Contrary to other big tech companies, IBM already existed when I was born in 1956. The company was in the business of computing even before the transistors. IBM adapted itself to electronics and dominated the industry in the era of big central mainframes. It survived the PC revolution when Microsoft and Apple were kings. They navigated the turbulent waters of the social Web despite the might of Google, Facebook, and Amazon. IBM is today one of the biggest players in the market for cloud computing, artificial intelligence and business consulting.

The transitions and transformations in IBM’s history were not only technological but also cultural. In the seventies, when I was a young philosopher and new technology enthusiast, IBM was the epitome of the grey suit, blue tie, black attache-case corporate America. Now, every IBM employee – from the CEO Dino Trevisani to the salesman – wears jeans. IBM used to be the “anti-Apple” company but now everybody has a Mac laptop. Instead of proprietary technology, IBM promotes open-source software. IBM posters advertise an all-inclusive and diverse “you” across the specter of gender, race, and age. Its official management and engineering philosophy is design thinking and, along with the innovative spirit, the greatest of IBM’s virtues is the ability to listen!

Toronto’s Forum was all about innovation and disruption. Innovation is mainly about entrepreneurship: self-confidence, audacity, tenacity, resilience and market orientation. Today’s innovation is “agile”: implement a little bit, test, listen to the clients, learn from your errors, re-implement, etc. As for the disruption, it is inevitable, not only because of the speed of digital transformation but also because of the cultural shifts and the sheer succession of generations. So their argument is fairly simple: instead of being disrupted, be the disruptor! The overall atmosphere of the Forum was positive and inspirational and it was a pleasure to participate.

There were two kinds of general presentations: by IBM clients and by IBM strategists and leaders. In addition, a lot of stands, product demonstrations and informative mini-talks on various subjects enabled the attendees to learn about current issues like e-health and hospital applications, robotics, data management, social marketing, blockchain and so on. One of the highlights of the day was the interview of Arlene Dickinson (a well known Canadian TV personality, entrepreneur, and investor) by Dino Trevisani, the CEO of IBM Canada himself. Their conversation about innovation in Canada today was both instructive and entertaining.

From my point of view as a philosopher specialized in computing, Bryson Koehler (CTO for IBM cloud and Watson) made a wonderful presentation, imbued with simplicity and clarity, yet full of interesting content. Before being an IBMer Bryson worked for the Weather Channel, so he was familiar handling exabytes of data! According to Bryson Koehler, the future is not only the cloud, that is to say, infrastructure and software as a service, but also in the “cloud-native architecture“, where a lot of loosely connected mini-services can be easily assembled like Lego blocks and on top of which you can build agile and resilient applications. Bryson is convinced that all businesses are going to become “cloud natives” because they need the flexibility and security that it provides. To illustrate this, I learned that Watson is not a standalone monolithic “artificial intelligence” anymore but is now divided into several mini-services, each one with its API, and part of the IBM cloud offer alongside other services like blockchain, video storage, weather forecast, etc.

BrysonImage: Bryson Koehler at the IBM innovation and disruption Forum in Toronto

Bryson Koehler recognizes that the techniques of artificial intelligence,  the famous deep learning algorithms, in particular, are all the same amongst the big competitors (Amazon, Google, Microsoft and IBM) in the cloud business. These algorithms are now taught in universities and implemented in open source programs. So what makes the difference in IA today is not the technique but the quality and quantity of the datasets in use to train the algorithms. Since every big player has access to the public data on the web and to the syndicated data (on markets, news, finance, etc.) sold by specialized companies, what makes a real difference is the *private data* that lies behind the firewall of businesses. So what is the competitive advantage of IBM? Bryson Koehler sees it in the trust that the company inspires to its clients, and their willingness to confide their data to its cloud. IBM is “secure by design” and will never use a client’s dataset to train algorithms used by this client’s competitors. Everything boils down to confidence.

At lunchtime, with a dozen of other influencers, I had a conversation with researchers at Watson. I was impressed by what I learned about cognitive computing, one of IBM’s leitmotiv. Their idea is that the value is not created by replicating the human mind in a computer but in amplifying human cognition in real-world situations. In other words, Big Blue (IBM’s nickname) does not entertain the myth of singularity. It does not want to replace people with machines but help its clients to make better decisions in the workplace. There is a growing flow of data from which we can learn about ourselves and the world. Therefore we have no other choice than to automate the process of selecting the relevant information, synthesize its content and predict, as much as possible, our environment. IBM’s philosophy is grounded in intellectual humility. In this process of cognitive augmentation, nothing is perfect or definitive: people make errors, machines too, and there is always room for improvement of our models. Let’s not forget that only humans have goals, ask questions and can be satisfied. Machines are just here to help.

Once the forum was over, I was walking in front of the Ontario lake and thought about the similarity between philosophy and computer engineering: aren’t both building cognitive tools?

Toronto-boardwalkImage: walking meditation in front of the Lake Ontario after the IBM innovation and disruption Forum in Toronto