what is science? the nature of science and scientific inquiry
Post on 21-Dec-2015
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What is Science?The Nature of Science and Scientific Inquiry
The Nature of Science
• Science is based on observations and inferences about the natural world (empirical evidence).
• Science is a creative human endeavor that is socially embedded.
• Scientific knowledge is always tentative (subject to change with new knowledge.
• Laws and theories are the products of science.
Hypotheses
• An hypothesis is a statement that predicts the outcome of an experiment.
• An hypothesis may be stated as a null hypothesis; that is, the hypothesis may predict no change.
• Hypotheses are tested by scientific inquiry.
• Tested hypotheses help build scientific knowledge.
Scientific Laws
• A scientific law is a description of a natural phenomenon.
• Laws are based on empirical evidence.
• Examples:
• Mendel’s laws of inheritance.
• The Hardy-Weinberg Law of population genetics.
• Laws may change with new knowledge.
Scientific Theories
• A scientific theory is an explanation of a natural phenomenon.
• Theories are based on empirical evidence.
• Examples:
• The theory of natural selection.
• Cell theory.
• Theories may change with new knowledge
Scientific Inquiry
• Scientific inquiry is the process that results in building scientific knowledge.
• There are three main types of inquiry (scientific studies):
• Descriptive
• Correlational
• Experimental
Descriptive Studies
• Descriptive studies describe the object of study in detail.
• Characteristic of young sciences.
• Some sciences, such as Astronomy and Taxonomy, rely almost entirely on descriptive studies.
Correlational Studies
• Correlational studies describe two events that occur at the same time, and look for a relationship between the two.
• Many health studies are correlational: they use large databases of health information, and try to answer questions when an experiment would be unethical.
• However, a correlation does not prove a cause.
Experimental Studies
• Experimental studies involve setting up control and experimental groups in order to the effects of one variable on another.
• Experiments can be used to determine cause.
• Experiments are used to test hypotheses (not to “prove” them).
Who is a scientist?
Who is a scientist?Ecologists
Who is a scientist?
Microbiologists
Who is a scientist?
Taxonomists
Who is a scientist?
Geneticists
Who is a scientist?
Botanists
Who is a scientist?
MolecularBiologists
Who is a scientist?
Zoologists
Science: A Human Endeavor