The Nature and Methods of Science

What is Science? Science is a body of knowledge based on the study of nature. The nature of science is scientific inquiry - the development of explanations. Scientific inquiry involves asking questions and processing information from a variety of reliable sources.

Scientific Theory V. Scientific Law A theory is explains how nature works. It is supported by a large body of scientific evidence Ex. Theory of Plate Tectonics A scientific law describes relationships under certain conditions in nature, but does not explain why the relationship is the way it is. Ex. Newton’s Laws of Motion

Science Expands Knowledge Most scientific fields are guided by research that results in a constant reevaluation of what is known. Pseudoscience imitate science, but do not provide science-based explanations - not based on the scientific method Examples: Astrology, Crystology

Challenges Accepted Theories Scientists welcome debate about one another’s ideas. Sciences advance by including new information as it is discovered. Data that is not consistent with current science are of interest to scientists. These differences often lead to further investigations

Challenges Accepted Theories

Science in Everyday Life A person who is scientifically literate combines a basic understanding of science and its processes with reasoning and thinking skills. Genetic engineering, cloning, genetic screening, euthanasia, and cryogenics all involve ethics. Ethical issues must be addressed by society based on the values it holds important.

Methods of Science

Observation Vs. Inference Scientific inquiry begins with observation - based on the five senses Conclusions based on the combination of what you already know with what you have learned are called Inferences. The first step of the scientific method involves asking a question based on observations

Form a Hypothesis (Step 2) A Hypothesis is a testable explanation of a situation. When a hypothesis is supported by data from multiple investigations, it is usually considered valid and is accepted by the scientific community.

Collect the Data (Step 3) When a biologist conducts an experiment, he or she investigates a phenomenon in a controlled setting to test a hypothesis.

Analyze the Data (Step 4) A graph of the data makes the pattern easier to grasp. Even when a hypothesis has not been supported, it is valuable.

Report Conclusions (Step 5) Biologists report their findings and conclusions in scientific journals. Before work can be published, it first must be peer reviewed. Peer review is a process by which the procedures used during an experiment and the results are evaluated by other scientists who are in the same field or who are conducting similar research.

Experimental Design Independent Variable- What you change or manipulate Dependent Variable - Depends on changes to the independent variable. Quantitative data can be measurements of time, temperature, length, mass, area, volume, density, or other factors. Qualitative data are descriptions of what our senses detect. The metric system uses units with divisions that are powers of ten. SI Units (International System of Units) are commonly used in science for consistency and ease of communication.