A system is more than a collection—each component is related to others, and changing one component affects the others. The featured articles in this issue describe how students can learn systems thinking (as well as content concepts).
The authors of Modeling Earth’s Climate describe a model that shows the interdependence and complexity of the components that affect climate. The suggested computer model (the URL is provided) lets students study feedback loops and test their hypotheses. [SciLinks: Global Warming and Global Climate Change]
Why Do I Crave That Cookie? is a question I often ask myself (although usually in the plural). The authors of this article have designed a set of activities in which students explore the relationships among body systems. A set of questions that drive the unit is suggested—for example: How do I know I’m hungry? Where is the cookie? What happens to food in my stomach? How do nutrients get to other parts of the body? This makes more sense than the typical lessons on each system.  [SciLinks: Body Systems]
A study of introduced species can exemplify what happens when an ecosystem is disturbed with, for example, a species with no native predator. Nonnative, Invasive, Exotic, Oh My! describes a such a study. [SciLinks: Invasive Species]

Classification systems are important in science. Engaging Students in Classifying Matter has ideas for helping students learn chemical and physical changes and properties. [SciLinks: Physical/Chemical Changes]
Many students view computer science as game-playing, without understanding the system behind the applications they use. The activities described in A Computer Story: Complexity from Simplicity use electric circuit construction, digital systems, base-n number systems, and truth tables to examine the decision-making that is the basis of computing. [SciLinks: Electrical Circuits]
All Things Being Equal describes an investigation into factors that affect the equilibrium of a system and includes questions that can be used as an assessment of student understanding. [SciLinks: Chemical Equilibrium, Factors Affecting Equilibrium, Le Châtelier’s Principle]
Scientific Discoveries the Year I Was Born doesn’t exactly address systems thinking, but the activity does show students that science isn’t just something that happened in the time of Galileo or Newton. By researching more recent discoveries and inventions, students can see that science and engineering are not just the domain of old folks. I must admit I looked up events from my birth year, including the use of radiocarbon dating and  the first recorded snowfall in Los Angeles.
Don’t forget to look at the Connections for this issue (October 2012), which includes links to the studies cited in the research article. These Connections also have ideas for handouts, background information sheets, data sheets, rubrics, etc.