Nature of Science

What are scientific models?

• Scientific models are representations of concepts, systems, or ideas.

• They take many forms, such as three- or two-dimensional objects or diagrams, mathematical equations, and computer simulations.

• Models are built from established scientific knowledge and observed patterns to predict patterns under different conditions or scenarios.

• They help explain and understand processes, phenomena, and ideas not easily observed or imagined.

• Models allow scientists to test ideas and predict outcomes that are difficult to test directly in the real world.

• They also allow testing the validity of other existing models.

• LEARNING COMPETENCY: Recognize that scientists use models to explain phenomena that cannot be easily seen or detected.

• LEARNING OBJECTIVES:

  • Recognize the various types of scientific models, such as physical, conceptual, mathematical, and computer models.

  • Describe commonly used models in science.

Types of scientific models

• Scientific models are commonly categorized into physical, conceptual, mathematical, and computer models.

• Physical models

  • Tangible objects that help one understand a concept or process.

  • A three-dimensional constructed copy of an original object that matches its characteristics, such as shape.

  • In some cases, a physical model represents an abstract idea.

  • They can be life-size replicas or scale models (smaller than the original object but otherwise identical).

  • Examples: a globe representing the Earth; a model of the human skeletal system.

• Conceptual models

  • Representations that use familiar objects or expressions to present a concept or an abstract and complicated idea.

  • They are also considered mental models (Victoria State Government 2020).

  • Example: the particle model of matter, which uses round particles to represent the composition of matter and explain observable properties.

  • Some conceptual models present a system of ideas that show general relationships (e.g., taxonomic classification of organisms, showing hierarchical groupings).

  • Other models are expressed through writing, speech, or action and are referred to as expressed models (Victoria State Government 2020).

  • Expressed models include diagrams and flowcharts. Flowcharts are structured diagrams of complex processes or scenarios that show key concepts, variables, and their relationships using arrows and shapes. Some flowcharts show decision options and corresponding outcomes in a process.

  • Example (flowchart in figure 1-2):

  • Does the computer turn on?

  • Yes / No

  • Are there any error messages?

  • Yes / No

  • Is the computer's power light on?

  • Yes / No

  • (Panel A) A simplified sequence; (Panel B) a more detailed flowchart involving steps like "search for the error message", "turn the monitor on", "check the power cord".

  • Figure 1-2: Conceptual models shown as (A) particle model of matter and (B) a flowchart.

• Mathematical models

  • Quantitatively represent relationships, patterns, and behaviors using equations.

  • Based on observations, theories, and measurements.

  • Contain numbers, characters, letters, and symbols.

  • Example: Newton's second law of motion, which describes the relationship among mass, acceleration, and the applied force on an object: F=ma.

• Computer models

  • Utilize computer software to study and simulate complex systems.

  • Usually highly mathematical in nature and involve processing of large datasets.

  • Widely used in all fields of science.

  • Example: In chemistry, the behavior of atoms and molecules is taught using computer simulations.

• Consensus models

  • Models that have been extensively tested and generally accepted by the scientific community.

  • Example: the big bang model (Victoria State Government 2020).

The role of models in science

• Models allow predicting outcomes under different conditions where direct testing may be difficult.

• They provide a framework to test ideas against observed data and other models.

• They help communicate complex ideas in a more approachable way.

• They are continually tested and revised as new evidence becomes available.

Galileo quote and scientific method context

• Quote: "All truths are easy to understand once they are discovered; the point is to discover them." — Galileo Galilei

• This emphasizes that science advances by discovering and verifying ideas through experimentation and observation.

• Since Galileo's time, experimentation has been used to validate ideas about the world and the universe.

• When scientists become curious, they observe, think, experiment, measure, analyze, and draw conclusions based on findings.

• This chapter guides you on how to do science the way scientists do, equipping you with knowledge about common models and tools used in science and how to properly utilize them in investigations.

Learning and course context

• PRE-LEARNING CHECK:

  • What are the common laboratory tools and their uses?

• What are the basic process skills employed in studying science?

• What are the components of a scientific investigation?

Objects and visuals referenced

• Figure 1-1: Physical models of the Earth (globe) and the human skeletal system.

• Figure 1-2: Conceptual models — (A) particle model of matter and (B) a flowchart.

Mini TEST 1-1

1. How do physical and conceptual models differ?

2. The Bohr model of the atom describes an atom as consisting of a nucleus at the center around which electrons revolve along specific orbits. What type of model is this?

3. Meteorologists use and process various complicated atmospheric information to come up with a daily weather forecast. What model will they most likely use? Why?

4. 4.

Summary of key ideas

• Models are representations of ideas or systems used to understand and predict phenomena.

• There are four main types of models: physical, conceptual, mathematical, and computer.

• Physical models are tangible and can be life-size or scaled copies.

• Conceptual models include mental models and expressed models like diagrams and flowcharts; they illustrate relationships and processes.

• Mathematical models express relationships using equations; they are quantitative.

• Computer models use software to simulate complex systems and often rely on mathematical formulations.

• Consensus models are well-tested, broadly accepted models such as the big bang model.

• Galileo’s quote highlights the importance of discovery and verification in science, with experiments forming a core basis for validating ideas.

• The chapter frames how scientists test ideas with observations, measurements, and analyses, guiding you through common models and lab tools used in investigations.

F=ma

• Key questions to consider:

  • What are scientific models?

  • What are the common laboratory materials used in scientific investigations?

  • How do scientists solve problems? SDS