Describe a system in terms of its subsystems and parts, as well as its inputs, processes and outputs.
Distinguish between open and closed systems.
Systems are a made of a series of interacting parts that work together to achieve a common goal. The systems have boundaries that separate it from its surroundings. Within those boundaries there may be smaller subsystems operating as well. Some systems are closed, meaning energy can enter or leave, but matter cannot. Other systems are open and allow matter and energy to move in and out of the boundaries.
Systems: "A system refers to a collection of objects that work together to achieve a specific goal. All systems have input, processes, outputs, feedback, and goals."
(Museum of Science, Boston, 2006)
Input: "Inputs include everything that goes in to the system in order to achieve the desired goal."
(Museum of Science, Boston, 2006) Inputs can include (but are not limited to) natural resources, tools, labor, time, training, energy, or physical resources.
Processes: "Processes describe the parts of the system that actually transform the inputs into the desired outputs." When you bake a cookie, the inputs are the ingredients and the processes are the actions involved in altering the ingredients to become the cookie. Examples: physical mixing of the batter, shaping the cookie in balls, and baking the batter
(Museum of Science, Boston, 2006)
Feedback: "Feedback provides information the system uses to make adjustments during manufacturing." Feedback is critical in the designed world systems, but may not fit in natural systems.
Output: "An output provides information that the system then uses to make adjustments."
(Museum of Science, Boston 2006)
MN Standard Benchmarks:
22.214.171.124.1: Describe a system in terms of its subsystems and parts, as well as its inputs, processes, and outputs.
126.96.36.199.2: Distinguish between open and closed systems
A quote, cartoon or video clip link directly related to the standard.
188.8.131.52: Honda Rube Goldberg Commercial This video can be used to introduce the idea of systems and subsystems. Students might count the number of subsystems they observe within the system. At the end of the unit, they might watch the video again and identify the machines within the subsystems.
- NSES Standards:
Unifying Concepts and Processes: Systems, Order and Organization
- AAAS Atlas:
- Benchmarks of Science Literacy
By the end of the 8th grade, students should know that
A system can include processes as well as things. 11A/M1
Thinking about things as systems means looking for how every part relates to others. The output from one part of a system (which can include material, energy, or information) can become the input to other parts. Such feedback can serve to control what goes on in the system as a whole. 11A/M2
Any system is usually connected to other systems, both internally and externally. Thus a system may be thought of as containing subsystems and as being a sub-system of a larger system. 11A/M3
Some portion of the output of a system may be fed back to that system's input. 11A/M4** (SFAA)
Systems are defined by placing boundaries around collections of interrelated things to make them easier to study. Regardless of where the boundaries are placed, a system still interacts with its surrounding environment. Therefore, when studying a system, it is important to keep track of what enters or leaves the system. 11A/M5** (SFAA)
- Common Core Standards
W.6.2. Write informative/explanatory texts to examine a topic and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.
Identify the systems of government that operate in our country. Then analyze the subsystems of the government systems.
Share that a system is like a topic sentence in a paper, and a subsystem is like a paragraph of information within a paper.
- Research done in connection with Science Curriculum Improvement Study (SCIS) indicates elementary students may believe that a system of objects must be doing something (interacting) in order to be a system or that a system that loses a part of itself is still the same system (Garigliano, 1975; Hill & Redden, 1985).
- Studies of student thinking show that, at all ages, they tend to interpret phenomena by noting the qualities of separate objects rather than by seeing the interactions between the parts of a system (Driver et al., 1985). Force, for instance, is considered as a property of bodies (forcefulness) rather than as an interaction between bodies. Similarly, students tend to think that whether a substance burns or not is being solely decided by the substance itself, whereas from a scientist's perspective, the process of burning involves the interaction of the burning substance and oxygen.
- When students explain changes, they tend to postulate a cause that produces a chain of effects one after another (Driver et al., 1985). In considering a container being heated, students think of the process in directional terms with a source applying heat to the receptor. From a scientific point of view, of course, the situation is symmetrical, with two systems interacting, one gaining energy and the other losing it (Driver et al., 1985).
- Concentrating on the inputs and outputs of a system often requires a different, time-independent view, which students may not take to be an explanation. Students often do not seem to appreciate that the idea of energy conservation may help explain phenomena. Studies reporting students' difficulties with energy conservation suggest students should have opportunities to describe systems both as sequences of changes over time and as energy inputs and outputs (a systems approach) (Brook & Driver, 1984).
- Student explanations of material change seldom include certain kinds of causes that are central to a scientific understanding of the world (Brosnan, 1990); for instance, that parts interact to produce wholes that have properties the parts do not. For children, wholes are like their parts. Brosnan (1990) summarizes all this by presenting two stereotypical views of the nature of change-the common-sense view and the scientific view (pp. 208-209)
Mrs. N's fourth-grade class is exploring how various parts of a system work together. She chose the bicycle as an appropriate system because children are familiar with it, and her students had recently learned in a social studies and technology unit that people all over the world rely on bicycles for their transportation needs. The students also had learned in their technology lab that other modes of transportation consume scarce resources and pollute the environment. Mrs. N brought her bicycle in and asked the class to explain how it worked. Bob volunteered that you just get on the bicycle and ride.
Caitlin says, "Well, you are pedaling, and that makes the wheels go." "But if you don't steer, you'll crash or tip over," Alice adds.
Pointing to the bicycle, Mrs. N restates the children's comments by observing that there are really several things happening: the rider is pedaling and steering, the wheels are turning, and the bicycle is moving.
Mrs. N then uses this explanation to introduce how many systems operate. There is input - in this case, energy coming from the rider pedaling the bicycle; a process, or something happening - pedals making the wheels turn; output - the bicycle moving; and a feedback loop - the rider observing that the bicycle is moving in the direction and speed that is desired.
After discussing the systems and experimenting with the bicycle, Jerome suggests, "Let's call this pedaling system the power system of the bicycle."
"Great idea. Is anything else happening?" Mrs. N asks. "Well, you have to steer," Jamie says.
"Would you consider steering to be a system also?" Mrs. N asks. Alice thinks for a moment and then answers in the affirmative. "What else?" she asks.
"You have to brake," Jamie notes.
"Would you consider the brakes to be a system also?" Mrs. N asks. After contemplating the question, Jamie decides that the input is the brake lever, the process is the brake pads acting on the wheels, and the output is slowing down or stopping.
"It would appear, then, that a technological system might be made up of several subsystems," Mrs. N concludes. "In the case of the bicycle, there is a power system, steering system, and braking system."
"Thinking about the unit we studied last week on machines, do you observe any simple machines in the bicycle?" Mrs. N asks.
"It has wheels and axles," Megan says.
"The chain sprocket is like a wheel too, and there is a pulley and a lever," Kendall says.
Tomorrow, Mrs. N will help the children discover the relationship between speed and the forces that produce rotation as they experiment with pedaling and shifting the upside-down bicycle. Although the students aren't ready yet for math calculations, Mrs. N plans to have them develop simple charts to depict the relationships.
Gears, sprockets, and chains will also tie the technology and science units together. Some of the students had already experimented with gears and chains by using the constructive building sets during their open discovery time.
Students need various opportunities to explore how technological ideas, processes, products, and systems are interconnected. For example, in the healthcare system technological devices that monitor the heart, blood pressure, and breathing are dependent on other technological devices, software, and hardware in order to perform properly. In the home, heating systems are dependent upon a thermostat system. If one aspect of a system is not functioning properly, the entire system may malfunction or break down. Students also can study relationships within technology by exploring the role of various occupations, such as engineering. (Standards for Technological Literacy, p. 49)/ITEA Connect
184.108.40.206.1: Systems and Subsystems
This website uses resources from Boston Museum of Science website and How it Works website to have students examine how "gadgets" are a system of interacting simple machines.
Purpose: To explore the parts of a system and develop students' understanding of the interactions between those parts. To engage in troubleshooting and design related to systems.
This lesson examines systems in the designing (and launching) simple rockets.
Film canisters can be purchased from a science supply company, if necessary.
220.127.116.11: One way to help students recognize the difference between a closed system and an open system is to explain that in a closed system, the output becomes the input. For example, an air conditioner unit runs cool air into a house. The air temperature in the house is measured by the thermostat. The thermostat sends a signal to the air conditioner when the air temperature is too high and needs to run. In this case, the temperature of the air is both the output and the input. However, in a ball point pen system, the person applies the input by manipulating the pen. The ink is the output. The ink does not control the pen. After explaining the difference to students, invite them to make a T chart in their science notebooks. Label one side "closed systems" and the other side "open systems." Students should work in learning groups to develop lists of closed and open systems that they encounter on a daily basis.
Once students recognize the difference between an open and closed system, it is appropriate to challenge them to construct an example of each. In the "Build a Damn" lab, created by TryEngineering.org, students are challenged to create a dam that holds and releases water, as necessary.
Vocabulary of the standard is identified in the Big Idea of Essential Understanding
Encourage students to bring in a discarded machine from home. An example might include a hand mixer, hair dryer, toaster, or small toy. Prior to class, use a wire cutter to cut off all electrical cords. Allow students time to analyze the machine by prompting them with questions such as, "Is this a closed system or an open system?" and "What subsystems do you believe make up this system?". Provide tools for students to "dissect" the machine and examine the subsystems, simple machines, and parts that work together to create the larger system.
Explore other uses of systems: Healthcare systems, political systems, economic systems, number systems, etc. This is a broad topic that enters into all content areas, and can be compared and contrasted with systems observed and studied in science throughout the year.
Identify an engineered system that you use every day. List the subsystems and the parts that make up the larger system.
If you could create a system that would complete a task to make your life easier, what would you make? What parts would be needed to make it work? Draw your system and label the subsystems.
How can the designed system in the vignette (a bicycle) be compared to a natural system?
What systems have students at this age level already experienced? How can you connect your lesson to these systems?
How will the learning about systems and subsystems help students as they continue on in their science and engineering coursework?
How does learning about systems and subsystems in science support students in other content areas?
Administrators should see students engaged in lessons that clarify the similarities and differences between the vocabulary terms by connecting the terms to concepts that the students have previously experienced. Students will be learning the terms in context and students should be able to apply this new knowledge in a hands on activity. For instance, students might disassemble a machine and identify the subsystems and parts within it. Advanced students might consider ways to develop a new and improved design that is less expensive, uses fewer parts, or is more efficient.
Struggling and At-Risk:
Most of today's school age children are part of a school system. Map out the parts of the system and how they interact. Dissect one small sub system within: the school they attend. How does it interact with other sub systems? What interactions occur within it? How do all of these parts and subsystems work together for a common goal?
Verbally name and label the systems and subsystems being identified by the class. Use multiple examples, including pictures and manipulatives.
Students design a Rube-Goldberg system to complete a predetermined task. The system should be made up of multiple subsystems, and each subsystem should contain three or more simple machines.
Tell students to explore a technology or "system" that was created in a country of their heritage. Students should research the system, identify its subsystems, and share their findings with classmates.
Provide students with small systems that they can manipulate, such as a clock. Take the cover and back off of the clock and show the students the subsystems inside it. Identify the simple machines that make up the subsystems.
Over break, parents can take their students to work and examine systems at work in the workplace. Explain how the systems are arranged to encourage order and work flow.
Identify the systems in your home that impact how we live. Ask your child, "How are people components of the systems in our home?"