Chapter 1: The Scientific Chapter 1: The Scientific MethodMethod

Leaving Certificate BiologyLeaving Certificate Biology

Higher LevelHigher Level

The Study of BiologyThe Study of Biology

• Biology is the study of living things

– Ecology

– Physiology

– Anatomy

The Scientific MethodThe Scientific Method1. Observation: taking in of information received about the

natural world2. Hypothesis: an educated guess/idea based on an

observation3. Experimentation: an experiment is a test designed to

prove/disprove a hypothesis4. Collection of data: data are results obtained after

carrying out an experiment5. Conclusions: explaining the results6. Analysis: explaining new knowledge in relation to

existing knowledge7. Reporting and publishing results: describing and

releasing results to other scientists and the public8. Development of theory and principle: a theory is a

comprehensive explanation; a law is a definite, factual explanation of an important aspect of nature

Principles of ExperimentationPrinciples of Experimentation• Careful planning and design• Safety (e.g. wearing gloves and lab coat)• Experimental control: a control is a factor in an

experiment that provides a standard upon which results may be compared

• Sample size: (larger sample size gives a better representation in the results)

• Random selection: (e.g. clinical trials must include younger people as well as older)

• Replicates: a replicate is a repeat of an experiment)

• Double-blind testing: (doctor does not know who has been given an active drug)

Limitations of the Scientific MethodLimitations of the Scientific Method

1. Extent of our basic knowledge: lack of knowledge leads to inadequate hypotheses

2. Basis of investigation: lack of technology/materials/equipment

3. Interpretation of results: scientists may interpret results differently

4. Application to a changing natural world: information obtained from organisms in the past may not be valid today – they may have to be repeated

5. Accidental discovery: experiments may have gone completely “wrong” – i.e. “we did not get the desired result” or “we made an error in preparation and an unexpected result is obtained”; e.g. discovery of penicillin