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What Is Ontology in Research? Definition & Types | CASRAI

Ontology is the branch of philosophy concerned with the nature of reality — what exists, what kinds of things exist, and how they relate to one another. In research, an ontological position determines whether the researcher assumes that social reality exists independently of human perception or is constructed through human interaction and interpretation.

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What ontology asks

Ontological questions include: Does an objective reality exist independently of human observers, or is reality constructed through the way people perceive and talk about it? Do abstract categories — social class, motivation, culture — have real existence, or are they useful fictions that researchers impose on a world of particulars? Does the same physical event have one correct description, or multiple equally valid ones depending on the observer's position? Researchers do not always address these questions explicitly, but their methodological choices implicitly embody an answer, which is why research training increasingly emphasises making ontological assumptions transparent.

Realism, idealism, and nominalism

Three broad ontological positions recur in the philosophy of science. Realism holds that reality — including social reality — exists independently of human minds and can be known, at least partially. Critical realism (Roy Bhaskar) is a sophisticated realist position that distinguishes between observed events and the underlying generative mechanisms that produce them. Idealism (or anti-realism) holds that reality is mind-dependent or linguistically constituted — we cannot step outside our conceptual schemes to access an independent world. Nominalism holds that only individual, particular things exist; the universal categories we use (species, social classes, emotions) are naming conventions, not real entities with existence beyond the particulars they label.

Objectivism and constructivism in social research

In social research, the ontological debate often takes a more specific form. Objectivism (or objectivism) holds that social phenomena — organisations, cultures, structures — have a real existence that is external to and constraining on individual actors, and that they can be studied independently of those actors. Social constructionism (or constructivism at the ontological level) holds that social reality is produced and reproduced through the interpretive activities of actors: meanings, categories, and institutions exist because people act as if they do and perpetuate them through interaction. The position chosen shapes everything from research design to how findings are interpreted and reported.

Ontology, epistemology, and methodology

Ontology, epistemology, and methodology form a chain of commitments. An ontological position (what exists) implies an epistemological position (how we can know what exists), which in turn implies methodological choices (how we conduct research to produce that knowledge). A realist ontology tends to support a positivist epistemology and quantitative methodology. A constructivist ontology tends to support an interpretivist epistemology and qualitative methodology. Pragmatism cuts across this chain by prioritising the research question over ontological and epistemological purity. Awareness of these connections helps researchers achieve internal consistency across their research design.

Key facts

At a glance

Definition: The philosophical study of the nature and kinds of existence
Core question: What exists, and does social reality exist independently of observers?
Realism: Reality exists independently of human minds and can be known
Idealism: Reality is mind-dependent or socially constructed
Nominalism: Only particulars exist; universal categories are naming conventions
In social research: Objectivism vs constructivism — the dominant ontological debate

Common misconceptions

What people often get wrong

Often heard: Ontology is only relevant to metaphysics, not to empirical research.

Actually: No — every research design embodies ontological assumptions about the nature of what is being studied. Making them explicit is now standard in doctoral methodology chapters and is assessed by examiners.

Often heard: Constructivism in ontology means research findings are made up.

Actually: No — social constructionism holds that social phenomena are produced through human interaction and interpretation, not that they are false or arbitrary. Research that takes this view can be rigorous, systematic, and empirically grounded.

Often heard: Realism means believing in a simplistic, unproblematic objective world.

Actually: No — sophisticated realist positions such as critical realism acknowledge that our access to reality is always mediated and that generative mechanisms may not be directly observable, while still maintaining that reality exists beyond our descriptions of it.

Going deeper