What Is Semiology? How Sign Systems Create Meaning

Semiology is the study of signs and how they produce meaning in human life. The term was coined by the Swiss linguist Ferdinand de Saussure in the early twentieth century, and it covers everything from spoken words and traffic lights to advertising images and medical symptoms. What makes semiology distinctive is its insistence that meaning is never simply “there” in an object or event; meaning is always constructed through a relationship between a sign and the system it belongs to. The word has also taken on a second, quite different life in medicine, where it refers to the interpretation of symptoms and clinical signs, a usage that predates Saussure and remains standard in many countries.

What a Sign Actually Is

Saussure proposed that every sign is made of two inseparable parts. One is the form you perceive: a sound, a written word, an image, a gesture. The other is the concept it calls to mind. The word “tree,” for instance, is a sequence of sounds (or letters) that triggers the mental concept of a tree. Neither half works alone. The sounds without a concept are just noise; the concept without some form to carry it stays locked in your head. And the link between the two is arbitrary: there is no natural reason why the sounds t-r-e-e should mean a tall woody plant. French speakers use a-r-b-r-e, and their signs work just as well.

This arbitrariness is the engine of semiology. Because signs are conventional rather than natural, they can be rearranged, combined, and subverted. A red octagonal sign means “stop” only because a community agreed it would. Swap the color to green and the convention breaks down. Semiology’s central project is to uncover these conventions, the invisible rules that let communities share meaning through signs of all kinds.

Semiology Versus Semiotics

You will encounter both “semiology” and “semiotics” in the wild, and people sometimes treat them as interchangeable. They share the same core subject, the study of signs, but they grew from different intellectual roots. Semiology descends from Saussure and the European structuralist tradition, emphasizing language as the master model for all sign systems. Semiotics traces primarily to the American philosopher Charles Sanders Peirce, who built a broader, three-part model of signs that includes the sign itself, the object it refers to, and the interpretation a mind produces from it. Peirce’s framework is often called triadic because of these three elements, while Saussure’s is called dyadic because it focuses on the two-sided relationship of form and concept.

In practice, the distinction has softened. Scholars in most English-speaking countries now use “semiotics” as the umbrella term, while “semiology” remains more common in French, Spanish, and Portuguese academic traditions. The medical use of “semiology” stands apart from both and carries no particular allegiance to Saussure or Peirce.

Denotation, Connotation, and Myth

Roland Barthes, a French cultural critic working in the mid-twentieth century, took Saussure’s framework and pushed it into everyday culture. His key insight was that signs operate on multiple levels. The first level is denotation: the straightforward, dictionary-style meaning. A photograph of a rose denotes a flower. The second level is connotation: the associative or emotional meanings layered on top. That same rose might connote romance, mourning, or political allegiance depending on context.

Barthes added a third level he called myth. In his framework, myth is what happens when a connotation becomes so widely accepted that it feels natural and inevitable rather than culturally constructed. His model treats myth as a second-order sign system, one that takes the signs already produced by denotation and connotation and recycles them to carry ideological weight, making cultural assumptions look like universal truths.

1International Journal of Educational Research Excellence (IJEREC). An Analysis of Roland Barthes’ Semiotic Theory: Focusing on Denotation, Connotation, and Myth

A concrete example of how this plays out comes from research applying Barthes’ framework to the concept of usury in finance. At the denotative level, usury is simply an additional charge on a debt. Connotatively, it carries meanings of exploitation and unfairness. At the mythic level, it gets repackaged into neutral-sounding financial concepts like revolving loans or brokerage fees, disguising the underlying dynamic of burden on borrowers.

2AL-MUZARA’AH. Mythologies of Usury in Finance: Analyzing Denotation, Connotation, and Cultural Myth using Roland Barthes’ Framework

Barthes’ layered model proved enormously influential for analyzing advertising, film, fashion, and political messaging. It gave researchers a vocabulary for talking about how images and objects carry meanings that go far beyond their literal content. One important line of work applied this thinking to advertising images, arguing that pictures are not transparent reflections of reality but convention-based symbolic systems that require active cognitive processing, much like language does.

3Oxford Academic (Journal of Consumer Research). Images in Advertising: The Need for a Theory of Visual Rhetoric

Medical Semiology

If you study medicine in France, Spain, Brazil, or Chile, “semiology” means something quite specific: the systematic study of symptoms and signs of disease, along with the techniques of history-taking and physical examination used to elicit them. In medicine, signs are objective manifestations that a clinician can observe or measure, like a rash, a heart murmur, or an abnormal lab value. Symptoms are the subjective experiences reported by the patient, like pain or fatigue. Medical semiology is the discipline that teaches clinicians to read these signs and symptoms together as a coherent clinical picture.

4PubMed. Origin and development of the book Medical Semiology

The parallel to linguistic semiology is not accidental. In both cases, the practitioner is reading signs within a system: interpreting what a cluster of findings “means” in context, distinguishing signal from noise, and recognizing patterns. A single symptom in isolation is like a word without a sentence. The clinician’s skill lies in assembling the full picture, understanding which signs are meaningful, which are incidental, and how they relate to each other.

In psychiatry, the semiological tradition has taken on renewed importance. There is growing recognition that modern diagnostic classification systems have focused heavily on categorizing disorders while neglecting the careful description and analysis of individual signs and symptoms. Researchers have argued that semiological analysis can reveal specific psychiatric features in a patient that classification systems tend to flatten, and that psychiatry needs to better define and classify its signs and symptoms using both biological and psychological perspectives.

5PubMed. Making psychiatric semiology great again: A semiologic, not nosologic challenge

Seizure Semiology in Neurology

Neurology offers one of the most vivid examples of medical semiology in action. When a patient has epileptic seizures, the specific movements, sensations, and behaviors that occur during each seizure carry information about where in the brain the seizure originates. Neurologists call this seizure semiology, and it is a practical diagnostic tool, not an abstract theoretical exercise.

By carefully observing and recording what happens during a seizure, clinicians can narrow down which brain region is involved. This is especially valuable when brain imaging does not show an obvious structural abnormality. Seizure semiology is described as a simple and cost-effective tool that allows localization of the brain area generating seizures, and video recording of seizures has made it possible to identify new localizing signs and measure how reliably they point to a specific region.

6PubMed Central. Seizure semiology: its value and limitations in localizing the epileptogenic zone

For example, the direction in which a patient’s head forcefully turns during a seizure can indicate which side of the brain is involved. Research has shown that the timing of when the head turns has localizing significance: the shortest delay occurs in seizures starting in the frontal lobe, and the longest in seizures starting in the occipital lobe, consistent with how far the electrical activity has to travel to reach the brain’s eye-movement centers. An end-of-seizure head position opposite to the initial forced turn occurs in roughly a third of focal epilepsies and consistently points to the same side as the seizure origin.

7PubMed Central. Localizing and Lateralizing Significance of Initial, Mid-Ictal, and Ictal-End Head Position in Versive Seizures With Secondary Generalization

In childhood movement disorders, semiological analysis serves a similar purpose. When children present with involuntary movements, the type of movement (chorea, dystonia, stereotypies) and its distribution across the body help point toward specific genetic causes. Research cataloging these patterns has found, for instance, that generalized involuntary movements tend to appear earlier in life than focal ones, and that certain movement types cluster with specific genetic mutations, giving clinicians a road map from observable signs to underlying diagnosis.

8PubMed Central. The Genetic Landscape of Complex Childhood-Onset Hyperkinetic Movement Disorders

Signs on Screens

The explosion of digital communication has created a vast new territory for semiological analysis. Every icon, button, menu, and emoji on your screen is a sign that someone designed and that you interpret, usually without thinking about it. But the conventions underlying digital signs are anything but obvious, and getting them wrong has real consequences for usability.

Researchers have applied semiotic frameworks directly to the design and evaluation of user interfaces. One study developed a multi-layered framework for evaluating web interface signs such as navigation links, buttons, and thumbnails, finding that these elements are often poorly understood despite their importance. The framework identified five layers of meaning in interface signs, from their visual structure to their social and contextual implications, and produced guidelines for designing signs that users can interpret accurately with less effort.

9International Journal of Human-Computer Studies. Towards user–intuitive web interface sign design and evaluation: A semiotic framework

Icon design is another area where semiology meets practice. The challenge of designing a tiny graphic that communicates “save,” “share,” or “settings” to millions of people across cultures is, at bottom, a semiological problem. Research combining cognitive psychology and semiotics has examined how icons function as a graphic language in software interfaces, aiming to optimize how visual interaction delivers messages.

10Procedia Engineering. Icon Design Study in Computer Interface

Semiotic analysis has also been used to explain why certain interface redesigns succeed or fail. When a designer changes how elements are arranged or represented on a screen, they are restructuring a sign system, and the principles of semiology can help articulate what changed and why users respond the way they do.

11ResearchGate. The Semiotics of User Interface Redesign

Then there are emojis, which have evolved from decorative flourishes into genuine semiotic resources. Research has found universal adoption of emojis in digital communication, with usage patterns that vary significantly by age group, confirming that these tiny pictographs now play a fundamental role in how people make meaning online.

12Language & Communication. The semiotics of emojis & emoticons: Social hierarchies, platform preferences, and functional implications in digital discourse

Architecture, Music, and Translation

One of the more surprising applications of semiology is in architecture. Buildings and spaces communicate, whether their designers intend it or not. A narrow corridor with a low ceiling signals something different from a soaring atrium, and these spatial signs operate through conventions that vary across cultures. Researchers have used semiological methods borrowed from linguistics to decode the meanings embedded in architectural forms. In one study of traditional residential architecture in the Iranian city of Bushehr, a semiological approach treated the architectural system as a system of signs, analyzing how forms and spatial arrangements carry layered cultural meanings about privacy, hospitality, and social hierarchy.

13ScienceDirect (Elsevier / HBRC Journal). Space and place concepts analysis based on semiology approach in residential architecture: The case study of traditional city of Bushehr, Iran

Music presents its own fascinating semiological puzzle. Unlike language, music does not have dictionary definitions. A melody does not “denote” an object the way a word does. Yet music obviously means something to listeners, and researchers in cognitive semiotics have tried to account for how. One influential line of argument holds that musical meaning is grounded in the body: experiencing music articulates your inner sense of space and time, creating a feeling of movement and vitality. At the most basic level, you perceive another person (the musician) manifesting through sounds, and through empathy, their expressive gestures evoke corresponding bodily responses in you. This grounds music as a semiotic system, even though it operates on a fundamentally different level from language.

14Public Journal of Semiotics. Musical Meaning and the Semiotic Hierarchy: Towards a Cognitive Semiotics of Music

Translation between sign systems is another area where semiological thinking proves useful. When a novel is adapted into a film, or a painting inspires a piece of music, something is being “translated” between fundamentally different kinds of signs. Researchers have investigated what it means to translate between sign systems, questioning whether the term “translation” is being used metaphorically or whether it genuinely extends to cover movement between semiotic modes like verbal language and visual media.

15Semiotica. Intersemiotic translation: Theories, problems, analysis

Semiology and Artificial Intelligence

The rise of large language models has given semiology an unexpected new testing ground. These systems process language at a scale and speed no human can match, but whether they actually engage with meaning in any semiological sense is an open question. A recent analysis argued that basic language models exist in what the authors called a “hall of mirrors,” reflecting the linguistic surface of their training data without any grounding in a shared external world. They manipulate symbols without participating in the social processes through which human communities create and negotiate meaning.

16Philosophy & Technology. Language Models’ Hall of Mirrors Problem: Why AI Alignment Requires Peircean Semiosis

The same researchers noted that newer developments, such as extended context windows, persistent memory, and the ability to interact with external environments, are moving AI systems closer to something that might qualify as genuine sign interpretation in Peirce’s sense. They identified no fundamental architectural barrier preventing this, but the gap between shuffling symbols and genuinely interpreting signs remains wide. The question of whether an AI system can truly participate in semiosis, or merely simulate the surface patterns of it, is one of the more philosophically charged problems in the field right now.

Legal Language as a Sign System

Law is built on language, and legal language is notoriously specialized. Semiological analysis has been applied to forensic and legal linguistics, treating the language of the courtroom, of contracts, and of evidence as a sign system with its own conventions and interpretive rules. The language of a legal process carries meaning not just through what words denote but through how they are deployed: the choice between “alleged” and “accused,” the passive voice that erases agency, the ritualized phrasing of oaths and verdicts.

17International Journal for the Semiotics of Law РRevue internationale de S̩miotique juridique. Semiotic Perspectives on Forensic and Legal Linguistics: Unifying Approaches in the Language of the Legal Process and Language in Evidence

Forensic linguistics, the analysis of language as evidence, relies on similar principles. When an investigator examines a threatening letter or a disputed contract, they are doing semiological work: reading not just what the text says but how it says it, what conventions it follows or violates, and what those patterns reveal about authorship, intent, or authenticity. The formalization of these practices owes a real debt to the broader tradition of sign analysis that semiology established.

Across all of these domains, from the clinic to the courtroom, from the concert hall to the smartphone screen, semiology provides a shared vocabulary for a basic human activity: making sense of signs. The specific methods and frameworks vary enormously depending on the field, but the underlying question stays the same. Something is present, something else is understood. Semiology asks how that leap happens and what conventions make it possible.