Unit 1 Methods of Science: Hypothesis Law Theory Model

Read Sections 1.1 – 1.3 prior to viewing the slides.

Topics for Unit 1 Basic characteristics of science (1.3) –Hypothesis – testable and reproducible –Law – summary of many observations –Theory – tentative attempt to explain observations –Model – attempt to explain abstract ideas with more familiar scale examples

Hypothesis A hypothesis is an educated guess that is testable Hypotheses (plural of hypothesis) are tentative explanations of phenomena that can be tested by further experimentation

Testable vs. Untestable Hypotheses The ability to test a hypothesis is a key element of its viability. A testable hypothesis is one for which experiments may be designed to determine absolutely whether the hypothesis is false. Such a hypothesis typically involves some sort of quantitative (numerical) determination. An untestable hypothesis is one for which no determination may be made as to its validity. Examples of untestable data include emotions, perceptions, etc.

Law A law is a brief summary of large amounts of scientific data –A law does not attempt to explain why something happens – it simply states that is does –A law is universal – under the stated sets of conditions it has always been found to be true –Examples: The law of the conservation of mass, the law of gravity

Theory A theory provides a detailed possible explanation as to why something is observed –Theories are tentative – they can be modified or discarded based upon new evidence –Theories provide predictive capability –Examples: Theory of Relativity, Kinetic- Molecular Theory

Model A model attempts to explain abstract phenomena with tangible approaches –A model is often used to help picture the description of a process provided by a theory –Example: The processes in a gas can be envisioned as similar to billiard balls hitting each other – this lends a tangible visualization to the kinetic molecular theory