- Organization. Scientists have made the study of science manageable
by organizing and classifying natural phenomena. For example, natural
objects can be assembled in hierarchies (atoms, molecules, mineral
grains, rocks, strata, hills, mountains, and planets). Or objects can
be arranged according to their complexity (single-celled amoeba,
sponges, and so on to mammals).
Primary grade children can be introduced to this concept by sorting
objects like leaves, shells, or rocks according to their
characteristics. Intermediate grade children can classify vegetables
or fruits according to properties they observe in them, and then
compare their own classification schemes to those used by scientists.
- Cause and effect. Nature behaves in predictable ways. Searching
for explanations is the major activity of science; effects cannot
occur without causes. Primary children can learn about cause and
effect by observing the effect that light, water, and warmth have on
seeds and plants. Intermediate grade children can discover that good
lubrication and streamlining the body of a pinewood derby car can make
it run faster.
- Systems. A system is a whole that is composed of parts arranged in
an orderly manner according to some scheme or plan. In science,
systems involve matter, energy, and information that move through
defined pathways. The amount of matter, energy, and information, and
the rate at which they are transferred through the pathways, varies
over time. Children begin to understand systems by tracking changes
among the individual parts.
Primary children can learn about systems by studying the notion of
balance--for example, by observing the movements and interactions in an
aquarium. Older children might gain an understanding of systems by
studying the plumbing or heating systems in their homes.
- Scale refers to quantity, both relative and absolute.
Thermometers, rulers, and weighing devices help children see that
objects and energy vary in quantity. It's hard for children to
understand that certain phenomena can exist only within fixed limits of
size. Yet primary grade children can begin to understand scale if they
are asked, for instance, to imagine a mouse the size of an elephant.
Would the mouse still have the same proportions if it were that large?
What changes would have to occur in the elephant-sized mouse for it to
function? Intermediate grade children can be asked to describe the
magnification of a microscope.
- Models. We can create or design objects that represent other
things. This is a hard concept for very young children. But primary
grade children can gain experience with it by drawing a picture of a
cell as they observe it through a microscope. Intermediate grade
children can use a model of the earth's crust to demonstrate the cause
of earthquakes.
- Change. The natural world continually changes, although some
changes may be too slow to observe. Rates of change vary. Children
can be asked to observe changes in the position and apparent shape of
the moon. Parents and children can track the position of the moon at
the same time each night and draw pictures of the moon's changing shape
to learn that change takes place during the lunar cycle. Children can
also observe and describe changes in the properties of water when it
boils, melts, evaporates, freezes, or condenses.
- Structure and function. A relationship exists between the way
organisms and objects look (feel, smell, sound, and taste) and the
things they do. Children can learn that skunks let off a bad odor to
protect themselves. Children also can learn to infer what a mammal
eats by studying its teeth, or what a bird eats by studying the
structure of its beak.
- Variation. To understand the concept of organic evolution and the
statistical nature of the world, students first need to understand that
all organisms and objects have distinctive properties. Some of these
properties are so distinctive that no continuum connects them--for
example, living and nonliving things, or sugar and salt. In most of
the natural world, however, the properties of organisms and objects
vary continuously.
Young children can learn about this concept by observing and arranging
color tones. Older children can investigate the properties of a
butterfly during its life cycle to discover qualities that stay the
same as well as those that change.
- Diversity. This is the most obvious characteristic of the natural
world. Even preschoolers know that there are many types of objects and
organisms. In elementary school, youngsters need to begin
understanding that diversity in nature is essential for natural systems
to survive. Children can explore and investigate a pond, for instance,
to learn that different organisms feed on different things.