Quantitative and Qualitative Observations
Objectives: After completing the lesson, students will be able to:
Key Question: "How do scientists describe the world we live in?"
Students are asked to draw and describe a familiar object (a penny) from memory. This leads to an introduction of how a scientific experiment is performed, through an initial exploration of the unique properties of water. The student is required to make a hypothesis, and record quantitative and qualitative data in an organized manner. The lesson ends with an examination of the importance of observation in science, and the difference between an observation and an inference.
Time Required: 1-2 class sessions.
Part A: (optional)
Assessment: complete p. 7 of Inquiry Skills Activity Book.
Suggestions for Homework:
OUSD Science Content Standards (State of California Science Content Standards):
1-a through f, except c ( 7-a through e).
Bell, J.L. Soap Science. Reading, MA.: Addison-Wesley Publishing Company, 1993, p. 5.
Focus on Earth Science: Laboratory Manual. Upper Saddle River, New Jersey: Prentice-Hall Inc., 2001, pp. 45-48.
Inquiry Skills Activity Book. Upper Saddle River, New Jersey: Prentice-Hall, Inc., 2001, pp. 5-8.
Project Earth Science: Physical Oceanography. Arlington, VA.: National Science Teachers Association, 1995, pp. 15-21.
Though not listed in the "Materials" section, it is a good idea to use some type of tablecloth or paper to cover the group tables. It is also a good idea to have sponges, rags, paper towels, and wash tubs on hand, in case of spillage. This is a good activity to emphasis safe laboratory procedures and the necessity to work as a group to avoid accidents.
atom: the smallest part of an element that can exist. It consists of a nucleus of protons and neutrons, surrounded by orbiting electrons.
element: a substance that cannot be broken down into more simple substances by chemical reactions.
hypothesis: prediction about the outcome of an experiment or observation.
molecule: the smallest unit of an element or compound. A molecule is made up of at least two atoms.
qualitative data: descriptions of events that do not use numbers If you report colors, smells, tastes, textures, or sounds, for example, you are making qualitative observations.
quantitative data: descriptions of events that do include numbers. If you count objects, or measure them with standard units, you are making quantitative observations. Quantitative observations are often made using tools.
surface tension: an effect that makes a liquid seem as though it has an elastic "skin." It is caused by cohesion between the surface molecules.