The Demarcation Spectrum

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About This MicroSim

This interactive MicroSim helps students assess where various knowledge claims fall on the spectrum from well-established science to pseudoscience using multiple demarcation criteria.. It supports the learning objectives in Chapter: Natural Sciences and the Scientific Method.

How to Use

Use the interactive controls below the drawing area to explore the visualization. Hover over elements for additional information and click to see detailed descriptions.

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

<iframe src="https://dmccreary.github.io/theory-of-knowledge/sims/demarcation-spectrum/main.html"
        height="450px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

9-12 (High School / IB TOK)

Duration

15-20 minutes

Prerequisites

• Familiarity with the concept of falsifiability and Karl Popper's demarcation criterion
• Basic understanding of what distinguishes scientific claims from non-scientific ones
• Exposure to at least one example of pseudoscience (e.g., astrology, homeopathy)

Learning Objectives

• Evaluate where knowledge claims fall on the demarcation spectrum between science and pseudoscience, using criteria such as falsifiability, peer review, and predictive power

Activities

1. Exploration (5 min): Individually, drag each claim card along the spectrum from "pseudoscience" to "science." Pay attention to how the placement feels intuitive for some claims (e.g., physics vs. astrology) but uncertain for others. Note which cards you found hardest to place and why.
2. Guided Practice (10 min): In pairs, compare your placements and check them against the expert view. For each card where you disagree, discuss: What criteria are you each using? Focus especially on gray-area cases like string theory, evolutionary psychology, or economics. Can a field move along the spectrum over time? Record at least two criteria that help distinguish science from pseudoscience.
3. Assessment (5 min): Choose one claim that sits in the gray area of the spectrum. Write a short paragraph (3-5 sentences) arguing for its placement, referencing at least two demarcation criteria (e.g., falsifiability, reproducibility, peer review, predictive success).

Assessment

• Accurate placement of at least 6 out of 8 claims within one position of the expert view
• Clear articulation of at least two demarcation criteria in the written justification
• Demonstrated awareness that demarcation is a spectrum rather than a binary distinction

Quiz

Test your understanding with this review question.

1. Which of the following best explains why the demarcation between science and pseudoscience is described as a "spectrum" rather than a sharp boundary?

1. Because all knowledge claims are equally valid regardless of methodology
2. Because some fields meet certain scientific criteria (e.g., falsifiability) but not others (e.g., reproducibility), placing them in a gray area
3. Because scientists disagree about whether science exists
4. Because pseudoscience always eventually becomes science with enough time

Show Answer

The correct answer is B. Many fields partially satisfy demarcation criteria -- for example, a discipline may generate testable hypotheses but struggle with reproducibility or peer review standards. This makes the boundary between science and pseudoscience gradual rather than absolute, which is why philosophers of science like Popper and Lakatos debated where to draw the line.

Concept Tested: The Demarcation Problem

References

1. Popper, K. (1963). Conjectures and Refutations: The Growth of Scientific Knowledge. Routledge.
2. Lakatos, I. (1978). The Methodology of Scientific Research Programmes. Cambridge University Press.
3. Pigliucci, M. (2013). The demarcation problem: A (belated) response to Laudan. In M. Pigliucci & M. Boudry (Eds.), Philosophy of Pseudoscience. University of Chicago Press.