How Does Science Work? TOK Students Explore the Nature of Scientific Knowledge

One of the central goals of modern education is helping students learn how to think, not just what to think. In today’s world, students are surrounded by information, claims, and opinions. Developing the ability to question evidence, evaluate ideas, and understand how knowledge is constructed is therefore an essential skill.

This idea lies at the heart of the IB Diploma Program’s Theory of Knowledge (TOK) course. TOK encourages students to step beyond the content of their subjects and examine a deeper question: How do we know what we know? Instead of focusing only on answers, students explore the processes through which knowledge is created, tested, and refined.

The natural sciences provides a powerful example of this process. While science classes often emphasize experiments and established theories, TOK invites students to look more closely at how scientific knowledge develops. Where do scientific ideas come from? What role does evidence play? And how certain can scientific conclusions really be?

To explore these questions, students recently took part in a collaborative activity centered on the question “How does science work?” Using an online resource from The Learning Behind the Science, students examined real examples that show science not as a fixed collection of facts, but as an evolving process of investigation, interpretation, and revision.

Working in small groups, students read through the material and discussed several guiding questions. They examined how scientists form ideas and hypotheses, and how evidence is used to support or challenge those ideas. They also explored the important distinction between observation, what scientists directly see or measure, and inference, which involves interpreting those observations to develop explanations. Understanding this distinction helps students see how scientific conclusions are built from evidence but also shaped by interpretation.

Another key idea students encountered was the role of uncertainty in science. Scientific knowledge is often presented as definitive, but it is always open to revision. New discoveries, improved technologies, or different interpretations of existing data can lead scientists to refine or even change previously accepted explanations. Recognizing this helps students understand that science is not simply about finding final answers, but about continually improving our understanding of the world.

For this activity, each student chose a different field of science, astronomy, biology, chemistry, geology, and physics, and considered the guiding question from the perspective of their chosen discipline. This approach allowed the group to see how the same question could be explored in multiple ways depending on the methods, assumptions, and kinds of evidence emphasized in each field. The diversity of perspectives enriched their discussions and highlighted the interconnectedness and variety of scientific approaches.

How Each Science Field Approached the Question

• Astronomy: Focused on interpreting observations of distant stars and galaxies, dealing with uncertainty in models, and understanding how evidence from light and movement informs theories about the universe.
• Biology: Emphasized experiments and careful observation of living systems, highlighting how evidence builds understanding of life processes and adapts with new discoveries.
• Chemistry: Examined controlled experiments, reactions, and molecular behavior, showing how evidence supports hypotheses and theories in predictable yet testable ways.
• Geology: Looked at Earth’s history through rocks, fossils, and geological processes, illustrating how scientists infer long-term patterns from present-day observations.
• Physics: Explored laws and patterns through mathematical reasoning and experiments, emphasizing consistency, prediction, and revising models when new evidence appears.

After discussing their ideas, each group was asked to create a podcast explaining what they had learned. The challenge was to communicate their understanding clearly: introduce their topic, explain one or two key ideas about how science works, use an example from the reading, and reflect on why these ideas matter for our understanding of knowledge.

The podcast format encouraged students to communicate their thinking collaboratively and clearly. Instead of simply writing answers, they needed to explain concepts in their own words and respond to the ideas of their group members. In many ways, this conversational approach mirrors how knowledge develops in the real world, through discussion, questioning, and the exchange of perspectives.

Through this activity, students began to see science differently. Scientific knowledge does not emerge fully formed from a single experiment or a single scientist. Instead, it develops gradually through observation, creative thinking, testing of ideas, and careful evaluation of evidence. Scientists must interpret results, consider alternative explanations, and remain open to revising their conclusions.

These insights connect directly to the broader aims of the Theory of Knowledge course. TOK encourages students to think critically about the strengths and limitations of different ways of knowing. By examining how science works, students gain a deeper appreciation for why scientific knowledge is often considered reliable, while also understanding that it remains open to challenge and improvement.

The podcast project allowed students not only to explore these ideas but also to practice important academic skills such as collaboration, communication, and critical thinking. Most importantly, it helped them recognize that knowledge, scientific or otherwise, is not simply something we receive. It is something people actively build, question, and refine over time.

Below is one of the student podcasts created as part of this activity:

Listening to students explain these ideas in their own words provides a glimpse into how they are beginning to engage with one of TOK’s central questions: How do we know what we know?