Nature of Science: Foundations and Processes in Scientific Inquiry

Nature of Science

Introduction to the Nature of Science

The nature of science refers to the systematic approach used to understand the world through observation, experimentation, and evidence-based explanations. Scientific knowledge is built upon empirical evidence and must be substantiated by other scientists.

• Science is a way of knowing about the world, limited to explanations based on observations and experiments.

• Explanations not based on empirical evidence are not considered scientific.

• Scientific understanding evolves with new findings and discoveries.

Key Scientific Terms

• Fact: An objective, verifiable observation. Example: Water boils at 100 degrees Celsius.

• Principle: A statement based on repeated experimental observation that describes an aspect of the world. Example: Greenhouse effect.

• Law: A broad concept or principle that describes patterns in nature (explains how). Examples: Newton's laws of motion, Boyle's gas laws, Law of Conservation of Mass.

• Theory: An explanation of an observed phenomenon that organizes facts and research to explain why. Example: Evolutionary theory. Note: A theory never becomes a fact or a law.

Scientific Method and Experimental Design

General Sequence of Scientific Investigation

Scientific investigations typically follow a logical sequence, though there is no single way to design an experiment.

1. Ask a question

2. Conduct background research

3. Construct a hypothesis

4. Test your hypothesis in an experiment

5. Analyze data

6. Draw conclusions and communicate them

Observations and Inferences

• Observation: Description of something you can see, smell, touch, taste, or hear. Must be objective and not an opinion. Example: The ground is wet.

• Inference: A guess about an object or outcome based on your observations. Multiple inferences can be made from a single observation. Examples: It rained; Someone was watering the plants.

Types of Observations

• Qualitative Observation: Describes qualities. Examples: Green liquid, large hole, sour taste, sweet smell.

• Quantitative Observation: Uses numbers to measure something. Examples: 4 feet long, 6 legs, 7.2 grams, 100 mL.

Considerations for Quantitative Data

• Precise: How close your measurements are to each other. Think: Is the data consistent? Is the data specific?

• Accurate: How close your measurement is to the correct/accepted value. Think: Is the data correct?

Always give the most specific reading on your instrument, then estimate one more decimal place.

Accuracy and Precision Comparison

Type	Description
Precise and Accurate	Measurements are both close to each other and to the true value.
Precise but not Accurate	Measurements are close to each other but not to the true value.
Accurate but not Precise	Measurements are close to the true value but not to each other.
Not Accurate or Precise	Measurements are neither close to each other nor to the true value.

Background Research and Purpose

• The goal of scientific investigation is to answer a question.

• Background research helps define the purpose or objective of the experiment.

• Purpose/Objective: A statement that clearly shows what question you are trying to answer in your investigation.

Constructing a Hypothesis

• Hypothesis: A testable prediction based on observations that describes a cause and effect relationship between variables.

• Format: "If (IV) then (DV)" IV = Independent variable (Cause) DV = Dependent variable (Effect)

Defining Variables

• Independent Variable (IV): What the experimenter deliberately changes or manipulates. Usually on the X-axis of a graph. Should be the only difference between experimental groups.

• Dependent Variable (DV): What changes in response to the independent variable. On the Y-axis of a graph. Represented by the data collected; what is measured.

Testing the Hypothesis: Materials and Procedures

• Materials: List all items needed, including amounts and brands if important. Be specific.

• Procedures: Write out every step taken, starting with an action word. Include every step for replication. Use a numbered list.

Experimental Design Considerations

• Experimental Group(s): Groups that are being tested.

• Control Group: Group used for comparison; the "normal" group.

• Constants: Aspects of an experiment held constant to ensure only the IV affects the DV. Example: All runners should be the same age, gender, breakfast, training, shoes, etc.

• Repeated Trials: Multiple trials ensure results are not due to chance, eliminate errors, and ensure data precision.

Analyzing Data

• Collect data in an organized form (e.g., data table).

• Present data in an easy-to-read way, such as a graph.

• Only make statements about what the data shows.

• Highlight trends or patterns.

• Discuss potential errors in the data.

Drawing Conclusions and Communicating Results

• Make an explicit statement about whether your hypothesis was supported or rejected by the data.

• Data may support or fail to support (reject) your prediction.

• Note: Data does not prove or disprove hypotheses.

• Describe real-world applications or uses for the information learned.

Science, Technology, and Engineering

Science vs. Technology

• Science: Advancement of knowledge; answers questions based on observations.

• Technology: Advancement of society; solves problems based on needs.

• Technology: Application of scientific discoveries to meet human needs and goals through products and processes.

• Engineering: Applies scientific and mathematical principles to solve problems.

Technological Design Process

• Problem Identification: Clearly define the problem or need.

• Solution Design: Brainstorm, research, sketch, and narrow down to the best design, considering constraints such as cost, time, and materials.

• Implementation: Build and test, continually making improvements.

• Evaluation: Determine if the problem was solved and all constraints were met.

Additional info: These foundational concepts are essential for understanding the scientific method and the role of science in society, forming the basis for all further study in biology and other sciences.