learner. If a problem fails to connect to legitimate and fundamental scientific ideas, it cannot be used to promote science learning. And if students fail to see the problem as meaningful, there is little chance that they will engage in the range of productive scientific practices that result in science learning.
Scientifically meaningful problems are framed by core concepts, such as biodiversity, the atomic-molecular theory of matter, and evolutionary theory, and they typically focus on the smaller concepts within those core ideas. Scientifically meaningful problems may be theoretical or practical. Theoretical problems are framed in terms of basic scientific ideas: How can matter be transformed? Why do objects lie at rest on the earth’s surface unless disturbed? Why are some species successful while others fail?
Practical or applied problems engage students in solving real problems in more immediate ways. For example, a unit on leverage and mechanical advantage might challenge students to think about and explore how a child could raise an adult off the ground using only a piece of 2 × 4 lumber as a lever and a cinder block as a fulcrum. Students might also engage in the application of science to broader societal issues. For example, they might explore the impact of an invasive species on a local woodlot and consider how to intervene to preserve the health of the local ecosystem. They might study the impact of a regional health problem, such as childhood obesity or asthma, and build a strategy for educating the community about risk prevention and treatment.
In addition to being scientifically meaningful, investigations must be meaningful to the person conducting the investigation. But what does it mean for a problem to be meaningful to a K-8 student? A meaningful problem must present an opportunity for something to be gained—practically or intellectually or both—from the investigation or outcome. In some cases, the benefits of solving a problem are easily recognized. For example, in the lever and fulcrum investigation, the problem posed and the resulting solution or outcome will be fairly easy for students to identify and appreciate. Students may also relate more easily to the curious phenomena they observe in their daily lives, such as what causes an empty juice box to crunch up when you suck continuously through a straw.
However, many concepts and problems worthy of investigation cannot be as easily linked to students’ own experiences, their existing knowledge, or issues they are familiar with and care about. In these cases, students may be less motivated initially to find meaning in a problem, and they may need to know more about it in order to become motivated to find that meaning. For example, many students