Domains of Science: A Structured Approach to Understanding

When someone says “science,” most people think of test tubes, lab coats, or memorizing the periodic table. But science is far more than a collection of facts stored in textbooks. Educators and philosophers of science broadly describe science through three interwoven domains: a body of knowledge, a process of inquiry, and a way of thinking. These aren’t separate compartments – they work together to create a complete, functioning picture of what science actually is. Understanding all three is essential for anyone who teaches or learns science, because it shifts the focus from simply knowing science to genuinely doing and thinking in science.

Science as a body of knowledge 🔗

Science consists of a body of knowledge built from centuries of observation, experimentation, and reasoning. This body of knowledge includes three key building blocks: facts, theories, and laws – and each plays a distinct role.

Facts 🔗

In science, a fact is not just anything we believe to be true. According to the National Center for Science Education, a scientific fact is an observation that has been repeatedly confirmed and is accepted as “true” for all practical purposes – though even facts remain open to revision if new evidence demands it. For example, the fact that Earth orbits the Sun was once fiercely contested but is now confirmed through multiple lines of evidence.

Theories 🔗

Perhaps no term in science is more misunderstood than “theory.” In everyday conversation, a theory is a guess. In science, it is the opposite. The US National Academy of Sciences defines a scientific theory as a comprehensive explanation of an important feature of nature, supported by facts gathered over time. Theories explain how and why phenomena occur. Darwin’s Theory of Evolution, Einstein’s Theory of General Relativity, and the Germ Theory of Disease are all well-substantiated explanations – not mere guesses. A theory does not become more valid by becoming a “law.” As Wikipedia’s entry on scientific theory notes, a theory will always remain a theory; a law will always remain a law – they do different things entirely.

Laws 🔗

A scientific law describes what happens in nature under specific conditions, often expressed mathematically. It predicts behavior but does not explain why that behavior occurs. A law predicts what happens; a theory explains why. Newton’s Law of Universal Gravitation, for instance, accurately predicts how objects attract each other based on mass and distance – but it does not explain the underlying mechanics of gravity. That explanation belongs to Einstein’s Theory of General Relativity. Both are essential and complementary parts of the scientific body of knowledge.

Importantly, this body of knowledge is not static. One of the hallmarks of scientific knowledge is that it is subject to change as new data emerge and existing data are reinterpreted. Major theories supported by multiple lines of evidence rarely change completely, but they are regularly refined and expanded.

Science as a process of inquiry 🔗

If the body of knowledge is the product of science, the process of inquiry is the method by which that product is created. Science is more about doing than knowing. At its core, scientific inquiry involves a cycle of observation, questioning, hypothesis formation, experimentation, and conclusion – though this cycle is rarely as linear or tidy as textbooks suggest.

Observation: the starting point 🔗

Every scientific investigation begins with observation. Observations are listed as the first step in the scientific method because they often provide a starting point – a source of questions a researcher may ask. Observations can be as simple as noticing that monarch caterpillars consistently feed on milkweed over other plants, or as complex as detecting gravitational waves from colliding black holes. Both begin with careful, systematic attention to the natural world.

Hypothesis formulation 🔗

An observation typically triggers a question, and a question leads to a hypothesis. According to the National Center for Science Education, a hypothesis is a tentative statement about the natural world that leads to deductions that can be tested. It is not a random guess – it is an educated, evidence-informed proposal. A well-formed hypothesis must be both testable and falsifiable. If there is no conceivable way to prove it wrong, it falls outside the domain of science. The hypothesis serves as a guide to the full process of scientific inquiry, shaping which experiments are designed and which data are collected.

Experimentation and data collection 🔗

Testing a hypothesis requires a carefully designed experiment. NOAA’s science education resources describe this stage as defining variables, running the experiment, and carefully recording data. Scientists distinguish between independent variables (what is deliberately changed) and dependent variables (what is measured as a result). Control groups – conditions kept constant for comparison – are central to ensuring that results reflect the effect of the variable being tested and nothing else.

Analysis, conclusions, and revision 🔗

After data are collected, they must be analyzed and interpreted. The scientific method is not a stepwise recipe – it is a continuous refinement and testing of ideas based on new observations. If results do not support the original hypothesis, the hypothesis is revised or replaced. If they do, the findings are communicated, often through peer-reviewed publication, where other scientists evaluate the work. This peer-review process is a critical check that keeps the body of scientific knowledge reliable and accountable. As Visionlearning explains, scientific knowledge builds on previous ideas and is constantly growing through this iterative process.

It is also worth noting that inquiry in authentic science is not confined to a single method. Depending on the field, scientists may use observational studies, field investigations, computer modelling, or historical data analysis – all valid forms of inquiry that contribute to scientific knowledge.

Science as a way of thinking 🔗

The third domain of science is perhaps the most profound and the least discussed in classrooms. Science is more than just a body of knowledge; it is a way of thinking that provides a means to evaluate and create new knowledge without bias. This scientific mindset shapes how questions are asked, how evidence is weighed, and how conclusions are drawn – and it is something anyone can develop, not just professional researchers.

Evidence-based reasoning 🔗

At the foundation of scientific thinking is a commitment to evidence. Scientists use objective evidence over subjective evidence to reach sound and logical conclusions. Objective observations – those based on measurable, verifiable data rather than personal bias – are the gold standard. This means that in science, a claim is only as strong as the evidence that supports it. No matter how elegant or intuitive a theory seems, it must stand up to empirical scrutiny. The scientific method is principally based on three modes of thought: empiricism, logical reasoning, and a skeptical attitude – without which critical thinking in science could not function.

The role of background knowledge 🔗

Scientific thinking does not happen in a vacuum. A scientist’s existing knowledge – their training, their familiarity with prior research, their understanding of related fields – actively shapes how they interpret new observations. Explanations aren’t merely intuition – they are informed by a scientist’s broad knowledge and experiences. A biologist studying animal behavior brings an ecological lens. A chemist analyzing a reaction brings knowledge of molecular structures. This background knowledge is not a source of bias to be eliminated; it is a resource that guides meaningful inquiry.

At the same time, thinking scientifically does not mean rejecting your culture and background, but recognizing the role they play in your way of thinking. Awareness of potential bias is itself part of scientific thinking. Scientists reduce the influence of personal assumptions through peer collaboration, controlled experimental design, and the transparency of published methods.

Skepticism, creativity, and open-mindedness 🔗

Scientific thinking also involves a productive tension between skepticism and creativity. Skepticism means not accepting claims without sufficient evidence – not even widely held ones. But generating a new hypothesis or devising an original experiment requires creativity and imagination. Scientists use their creativity and imagination at all stages of scientific investigation – from choosing what to study to deciding how to test their ideas. Far from being purely mechanical, science is a deeply human enterprise that combines rigorous discipline with genuine intellectual curiosity.

How the three domains work together 🔗

The body of knowledge, process of inquiry, and way of thinking are not isolated from each other – they are deeply interdependent. The body of knowledge provides the theoretical framework and factual foundation that guides scientific inquiry. The process of inquiry tests and expands that knowledge. The way of thinking ensures that both the inquiry and the knowledge remain grounded in evidence, open to revision, and free from dogma.

A research scientist testing a new drug, for instance, draws on existing knowledge about biochemistry and disease mechanisms (body of knowledge), designs a controlled clinical trial (process of inquiry), and evaluates the results with an evidence-based, skeptical mindset (way of thinking). Remove any one domain, and the enterprise falls apart. Achieving scientific literacy requires a broader view of science that includes the knowledge of science, the methods of science, and the nature of science – all three working in tandem.

For educators, this has a direct implication. Teaching science only as a body of facts to be memorized addresses just one-third of what science actually is. When students also learn how scientific knowledge is produced and how scientists think, they develop the tools to evaluate evidence, challenge misinformation, and engage meaningfully with the science that shapes the world around them.

What do you think? Does your current approach to teaching or learning science engage equally with all three domains – knowledge, inquiry, and thinking – or does one tend to dominate? And how might classrooms look different if scientific thinking were treated as a core skill alongside content knowledge?

References

1. https://www.visionlearning.com/en/library/Process-of-Science/49/The-Nature-of-Scientific-Knowledge/185
2. https://ncse.ngo/definitions-fact-theory-and-law-scientific-work
3. https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introductory_Chemistry_(LibreTexts)/01:_The_Chemical_World/1.06:_Hypothesis_Theories_and_Laws
4. https://en.wikipedia.org/wiki/Scientific_theory
5. https://science.howstuffworks.com/innovation/scientific-experiments/10-scientific-laws-theories.htm
6. https://bio.libretexts.org/Bookshelves/Human_Biology/Human_Biology_(Wakim_and_Grewal)/01:_The_Nature_and_Process_of_Science
7. https://coursecontent.umgc.edu/umgc/shareable-content/toolkits/GNSC000/S4-The_Scientific_Method.html
8. https://app.jove.com/science-education/v/10649/scientific-method-observation-hypothesis-and-experiment
9. https://www.nesdis.noaa.gov/about/k-12-education/resources-teachers/what-the-scientific-method
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC8550242/
11. https://open.library.okstate.edu/culturalgeography/chapter/1-2/
12. https://slcc.pressbooks.pub/physicalgeography/chapter/1-1/
13. https://raggeduniversity.co.uk/2014/02/13/scientific-method-2/
14. https://letstalkscience.ca/educational-resources/backgrounders/understanding-science
15. https://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=1330&context=jmsce_vamsc