Scientific Knowledge (LC 2027) (Leaving Cert Biology): Revision Notes
The Nature Of Scientific Knowledge
What is science?
Science comes from the Latin word 'scientia', which means 'knowledge'. This etymology reflects the fundamental purpose of scientific inquiry - to build understanding of our world.
At its core, science is the organised study of the natural world that builds understanding through careful observation and controlled experiments.
What makes science special is that it's driven by curiosity and inquiry. Scientists ask questions about how the world works, then use evidence-based methods to find answers. Science is often divided into different areas like chemistry, physics, and biology, but they all share the same fundamental approach to understanding nature.
The key feature that sets science apart from other ways of understanding the world is that scientific knowledge must be evidence-based. This means that scientific claims need to be supported by observations and experimental results, not just opinions or beliefs.
The scientific method
The scientific method is the systematic approach that scientists use to investigate the natural world and build reliable knowledge. Think of it as a step-by-step process that helps ensure scientific discoveries are trustworthy and can be tested by others.
The main steps explained
Observation is where scientific inquiry begins. An observation means noticing something interesting or unusual in the natural world.
Practical Example: Baby's Skin Rash
A parent notices their baby gets a skin rash after eating a new food. This observation leads to questions that need investigating - could the new food be causing the rash?
Hypothesis comes next. A hypothesis is a suggested explanation for what you've observed, and it must allow you to make a prediction that can be tested. It's important to understand that a hypothesis isn't just a wild guess - it should be an educated explanation based on what you already know. In our example, the hypothesis might be "the new food causes the baby's rash."
Experiment involves designing and carrying out a scientific test under controlled conditions to test your hypothesis. The parent might stop giving the new food to the baby for a period of time to see what happens to the rash. This controlled approach helps ensure that any changes you observe are actually due to what you're testing.
Results represent the information you gather during your experiment. This data (remember, the singular is 'datum') includes all your measurements, observations, and findings.
You need to distinguish between primary data (information you collect yourself through experiments or surveys) and secondary data (information collected by someone else that you might read about or hear in a podcast).
Conclusion involves analysing your results to decide whether your hypothesis should be accepted, rejected, or modified. If the baby's rash disappears when the new food is withdrawn, this supports the hypothesis. If the rash stays the same, the hypothesis would be rejected, leading to the formation of new hypotheses.
Communicating scientific knowledge
Science is a global enterprise that depends on clear communication between researchers worldwide. For scientific knowledge to be reliable and useful, it must be shared effectively through established systems and conventions.
Clear communication
Scientific writing needs to be clear and easy to understand. Traditionally, science was often written using passive voice (for example, "The temperature of the liquid was taken"), but modern scientific writing increasingly uses active voice ("I took the temperature of the liquid") because it's clearer and easier to follow.
When scientists write about their work, they must follow international conventions that make their research accessible to colleagues around the world. This includes using standardised measurement systems, following specific rules for mathematical symbols and formulas, and using proper referencing systems when citing other researchers' work.
Peer review
Peer review is one of the most important quality control mechanisms in science. When scientists complete their research, they submit their findings to scientific journals. The journal editors then send the work to other experts in the same field who evaluate the quality, accuracy, and significance of the research.
This peer review process ensures that published scientific articles meet high standards. The reviewers check that experiments were well-designed, that conclusions are supported by evidence, and that the work contributes meaningfully to scientific knowledge. Articles may be rejected, accepted, or require revision based on these expert evaluations.
Reproducibility
A crucial feature of good science is that experiments should be reproducible. This means that if other scientists follow the same procedures in different laboratories, they should get the same results. Reproducibility is what transforms individual findings into accepted scientific evidence.
When experiments can be successfully repeated by independent researchers, the findings become much more reliable and trustworthy. This is why scientific papers must include detailed descriptions of experimental methods.
From hypothesis to theory
Understanding the difference between hypotheses, theories, and principles is essential for grasping how scientific knowledge develops and becomes established.
A hypothesis is an educated guess based on observations that can be tested through experimentation. Hypotheses are often quite narrow in scope and may only explain a specific observation or phenomenon.
A theory represents a much higher level of scientific understanding. A theory is a hypothesis that has been supported by many different experiments conducted by various researchers over time. Theories are broader than hypotheses and can explain multiple related phenomena. Important examples include the theory of evolution and atomic theory.
A principle or law represents the highest level of scientific certainty. Principles are based on theories that have been valid when fully tested over long periods of time. They describe fundamental relationships in nature that appear to be universal.
The progression from hypothesis → theory → principle shows how scientific knowledge becomes more reliable and well-established through repeated testing and validation.
Bias in science
Bias represents unfair, unreasoned, or personal judgements that can affect scientific work. Scientists must be aware of potential sources of bias and work to minimise their impact on research.
Critical Questions for Evaluating Scientific Information:
When evaluating scientific information, you should ask these critical questions:
- Can the information be verified through reliable sources?
- Is it based on emotions rather than evidence?
- Is the author an expert in the relevant field?
- Is the report available from multiple sources?
- Is the source of the article from a reputable organisation?
Understanding bias is particularly important when consuming scientific information from media sources, which may present findings in ways that attract attention rather than accurately represent the scientific evidence.
How science changes over time
Scientific knowledge is not static - it constantly evolves as new evidence emerges and understanding improves. Scientific ideas change when new research provides better explanations for natural phenomena or when improved technology allows more precise observations.
This dynamic nature of science was clearly demonstrated during the COVID-19 pandemic, when scientific understanding of the virus and appropriate responses evolved rapidly as new evidence became available. Rather than being a weakness, this ability to revise and improve understanding based on new evidence is one of science's greatest strengths.
The scientific method is not a linear process but rather circular and iterative. As new discoveries are made, scientists often need to revise previous hypotheses, leading to new experiments and further discoveries.
Key Points to Remember:
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Science is evidence-based - scientific knowledge must be supported by observations and experimental results, not just opinions
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The scientific method provides a systematic approach - observation leads to hypothesis, which guides experiment design, results analysis, and conclusion formation
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Communication is crucial - peer review and reproducibility ensure scientific findings are reliable and trustworthy
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Scientific knowledge evolves - theories and understanding change as new evidence emerges, making science a dynamic and self-correcting process
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Bias awareness is essential - always critically evaluate scientific information by checking sources, expertise, and evidence quality