Science Curriculum Topic Study

Air & Atmosphere and Weather & Climate

IV. Examine Research on Student Learning

Benchmarks for Science Literacy

• Water cycle: Before students understand that water is converted to an invisible form, they may initially believe that when water evaporates it ceases to exist, or that it changes location but remains a liquid, or that it is transformed into some other perceptible form (fog, steam, droplets, etc.) With special instruction, some students in 5^th grade can identify the air as a permanent substance. Students understand rainfall in terms of gravity in middle school but not the mechanism of condensation, which is not understood until early high school.

Atlas for Science Literacy, Volume 2

• Weather & Climate: Students of all ages (including college students and adults) have difficulty understanding what causes the seasons. Many students think that the earth is colder in the winter because it is farther away from the sun. This idea is linked to ideas that the earth’s orbit is a long ellipse. Others are confused by distances, thinking that the earth is farther away from the sun in the winter because it is tilted away from the sun.
• Air: Upper elementary students understand that air takes up space. That air has weight is more difficult to understand. Students of all ages may believe that air exerts force or pressure only when it is moving and only downwards. Only a few middle school students use the idea of pressure differences between regions of the atmosphere to account for wind; instead, they may account for wind in terms of visible moving objects or the movement of the earth.
• Students of all ages confuse the ozone layer with the greenhouse effect, and may have a tendency to imagine that all environmentally friendly actions help to solve all environmental problems (for example, that the use of unleaded petrol reduces the risk of global warming).

Making Sense of Secondary Science: Research Into Children’s Ideas

• Existence of Air: Most 8 year olds recognized air as something you need to breather. By the age of 12, students know that air contains oxygen. Many students think of air in general terms of being related to ideas about solids, liquids, and gasses. By age 11 students know that air exists in open containers. Some children at this age were less sure that air was contained inside a sealed container. Some thought air existed only when it moved. Many young children think of air and smoke as having a transient character like “thoughts”. They do not understand the material nature of gas as having mass and taking up space. Most children’s experiences with gas and air is that it gases tend to rise or float. Most 8-12 year olds consider that air has no weight. A study with 12-13 year olds found that students think of air and gravity as inseparable: that things do not fall in space because there is no atmosphere and, in the absence of air, weight becomes zero. By the age of 16, many students know that the earth’s atmosphere changes with distance away from the earth’s surface. About half of 16 year olds will know that air is a mixture of components. By this age, they do know that air takes up space and that its volume can be changed.
• Air Pressure: At age 8, students recognize that air can push against things. Many 11-13 year olds think that wind and not still air has pressure and that it is the pressure that causes air to move. Students do not think in terms of pressure acting equally in all directions. They think there is greater pressure downwards. They used these same ideas to explain atmospheric pressure. Some thought of air as being sucked as through a straw or vacuum. Students by age 16 rarely account for wind in terms of pressure differences between regions of atmosphere. Rather, they account for wind in terms of visible moving objects and sometimes with movements of the earth or the coldness of the poles. They also equated wind speed with temperature: higher wind and colder temperatures and warmer winds as slower and gentler.

Resources:

§ American Association for the Advancement of Science. 2007. Atlas for Science Literacy. Volume 2. Washington, DC: NSTA Press.

§ American Association for the Advancement of Science. 1994. Benchmarks for Science Literacy. New York: Oxford University Press. Note: This document is also available on the web at: http://www.project2061.org/publications/bsl/online/bolintro.htm

§ Driver, R.; Squires, A.; Rushworth, P.; and Wood-Robinson W. 2000. Making Sense of Secondary Science: Research Into Children’s Ideas. London: Routledge.

§ Keeley, P. 2005. Science Curriculum Topic Study: Bridging the Gap Between Standards and Practice. Thousand Oaks, CA: Corwin Press.