Critical Thinking and The Scientific Method

GNED 1101: Critical Thinking and The Scientific Method

SCI LIT TEXT CHAPTER 4 – LOGIC, CRITICAL THINKING AND SCIENTIFIC METHOD

Quote by Carl Sagan: "We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology."
Assignment information: Scientific methods are due on October 3rd, duration of assignment is 40 minutes, and calculators are not allowed.

IMPORTANT DEFINITIONS

• Empirical: Source of knowledge acquired by means of observation or experimentation.

• Systematic: Methodical, regular, and orderly process of conducting research.

• Subjective vs. Objective:

  • Subjective: Open to interpretation; relies on opinions and personal experiences—typically qualitative.

  • Objective: Fact-based, measurable, and observable—typically quantitative.

  • Normative vs. Positive: Acknowledges the distinction between what ought to be (normative) and what is (positive).

TYPES OF SCIENTIFIC INQUIRY

• Science comprises both a process of inquiry and a body of knowledge resulting from it.

• Three Main Types of Inquiry:

  1. Descriptive Inquiry

  2. Comparative Inquiry

  3. Experimental Inquiry

1. Descriptive Inquiry

• Definition: Focuses on asking, "What's out there?"

• Purpose: Describes existing phenomena in nature; no manipulation of variables; merely observes and describes.

• Qualitative Observations: Must be as objective and specific as possible.

  • Example: Instead of saying "the hummingbird is beautiful," a more specific description would be: "the hummingbird has iridescent blue plumage on the head and a bright ruby red throat patch."

• Provides foundational knowledge for further studies.

  • Examples of Descriptive Studies:

  • Cataloguing plant species in a rainforest.

  • Calculating numbers of planets in the galaxy that may sustain life.

  • Sequencing genomes of organisms, like describing DNA and identifying genes related to disorders.

2. Comparative Inquiry

• Purpose: Aims to find correlations between phenomena or variables.

• Involves observing connections, relationships, or patterns among variables without manipulating them.

• Critical Note: Correlation does not imply causation! Just because two events occur together does not imply one causes the other.

  • Examples of Comparative Studies:

  • Studying causes of cancer in humans.

  • Investigating effects of human activity on climate change.

  • Correlation must be studied in detail to establish a causal relationship.

  • Retrospective Studies: Comparative inquiry often involves looking back at data, e.g., associations observed in various worker populations exposed to carcinogens like asbestos.

3. Experimentation

• Definition: The manipulation of variables under controlled conditions to infer cause-and-effect relationships.

• Process:

  • Researcher forms a hypothesis, manipulates a variable, records and analyzes results, and concludes about the hypothesis.

• Scientific Method: Central to experimentation, emphasizes the importance of repeatability.

WHAT IS THE SCIENTIFIC METHOD?

• A core discipline of critical thinking or scientific reasoning designed to review and repetitively verify ideas, reducing uncertainty about how the physical world operates.

• It involves a standardized process with a series of steps:

  • More than merely following a procedural formula; it encourages analytical thinking about results and the inquiry process.

• Quality control measures like peer review help eliminate outliers and strengthen the validity of conclusions.

• Cyclical Nature of the Scientific Method: Acknowledges that new information may prompt scientists to revisit and repeat steps.

6 STEPS OF THE SCIENTIFIC METHOD

1. Observation

2. Hypothesis

3. Experimental Design

4. Examine and Interpret Results

5. Evaluate Results (compare to hypothesis)

6. Peer Review and Publication

   • The peer review process is not the initial step but rather a quality assurance step following hypothesis testing and data collection.

1. Making Observations and Asking Questions

• Initiates scientific inquiry by leading to questions that need answering.

• Utilizes Inductive Reasoning: Draws general principles from specific observations.

  • Example: Noting that many people use Cold FX might lead to the question: Does it really work?

2. Create a Falsifiable and Testable Hypothesis

• Developed through research after forming an initial idea or “hunch.”

• Characteristics of a Hypothesis:

  • Must present a statement (not a question).

  • Utilizes clear, definitive language—avoid vague terms.

  • Must be falsifiable: Means it can be proven false through observation or analysis.

• Example: Cold FX works.

• Conditional statements can be used for testing hypotheses:

  • Premise form: If p (hypothesis), then q (prediction).

3. Design an Experiment to Test the Hypothesis

• Utilizes Deductive Reasoning: Moves from general rules to a specific conclusion, confirming or challenging the hypothesis.

• Example: Establishing that all bacteria contain DNA means that a newly discovered bacteria should also contain DNA.

DEDUCTIVE REASONING

• This approach leads to logically valid conclusions, as it operates on established truths.

  • Examples:

  • All cells have DNA. Therefore, elephant cells have DNA.

  • All noble gases are stable; Helium is a noble gas, therefore helium is stable.

SUMMARY: INDUCTIVE VS. DEDUCTIVE REASONING

• Inductive Reasoning: Moves from specific observations to general conclusions (may be true).

• Deductive Reasoning: Starts with general principles to arrive at specific truths (always true).

USING LOGIC TO TEST A SCIENTIFIC HYPOTHESIS

• Inductive reasoning formulates the hypothesis, while deductive reasoning is utilized for testing.

• The hypothesis forms the structure of logical arguments:

  • Conditional format: p → q (If p, then q).

• Evaluating the truth value of the hypothesis occurs through assessment of q.

DEDUCTIVE REASONING IN HYPOTHESIS TESTING

• Standard forms of arguments are important to validate conclusions based on observed data.

• Example:

  • Hypothesis (p): The MMR vaccine causes autism.

  • Prediction (q): There is a higher rate of autism among vaccinated children.

  • If results show no increased rate of autism, it concludes the hypothesis is false.

SCIENCE AND PROOF

• It’s imperative to note that science does not prove hypotheses to be true; it only demonstrates their potential falsehood.

• The ultimate goal is to reduce uncertainties, treating hypotheses as temporarily “true” until disproven.

STEPS OF SCIENTIFIC METHOD CONT’D

• Step 3 - Design an Experiment: Requires proper testing for logical validity.

• Step 4 - Examining and Interpreting Data: Involves collecting data and using deductive reasoning to analyze outcomes adequately.

• Step 5 - Evaluating Results: Determines if the original hypothesis has been disproven or remains valid; leads to the development of new theories as needed.

HYPOTHESIS VS. THEORY

• Hypothesis: Untested prediction formed through inductive reasoning, lacking robust evidence.

• Theory: Established concept supported by substantial evidence, thought to be true based on current knowledge.

  • Example: Theories evolve (like the theory of Continental Drift) and may be discredited with new evidence.

STEPS OF SCIENTIFIC METHOD CONT’D

• Step 6 - Peer Review, Evaluation, and Publication:

  • Highlights the quality assurance processes that research goes through for validity checks before publication.

• Peer review acts as a continuous quality control mechanism within the scientific community.

• Replicability of studies strengthens credibility; fraudulent or unreplicated studies may be identified over time.

CONCLUSION

• Review the learning objectives and be prepared for evaluations as they arise.

• Recognize the importance of the scientific method in establishing robust scientific knowledge and claims.