Happy Halloween!
Learning Target
Students will be able to evaluate different artificial materials for building a coral reef by identifying the criteria for reef success and the constraints.
Success Criteria
I am successful when I can....
1) Define criteria and constraints.
2) Compare multiple possible solutions to see which ones meet the criteria best.
3) Check whether each solution stays within the constraints (time, materials, cost, etc.).
4) Rank the solutions from strongest to weakest based on how well they meet the criteria AND stay within the constraints.
5) Justify my ranking using evidence about criteria and constraints.
Standards
HS-LS2-7.
Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity
Reminders
End of Marking Period is November 7th.
Tutoring Wednesdays, in A-301.
.
Part 1:
Learning about Criteria and Constraints when designing solutions
Every object we use, from a simple pencil to advanced medical devices, was carefully designed to solve a problem. Scientists and engineers both study the world, but they focus on different goals. Scientists work to understand how things work in nature, while engineers use scientific knowledge to design solutions to real-world problems. When engineering uses ideas from biology, it is called bioengineering. Bioengineers may design medical equipment, create new medicines, improve crops, or develop safer materials and technologies.
Scientists and engineers also ask different types of questions. A scientist studying a plant used in medicine might ask what chemicals in the plant help treat disease, how those chemicals work inside the human body, and whether the plant can be safely and sustainably grown. Their goal is to explain how the natural process works. An engineer, however, would ask questions about improving that medicine. They might ask whether the medicine can be made more effective, whether it can be produced in a lab instead of growing thousands of plants, or what the best way is to store and deliver the medicine to patients. While scientists focus on understanding, engineers focus on solving problems.
To design a solution, engineers first need a clear problem statement. For example, imagine designing a prosthetic leg for someone who has lost a limb. Simply saying “make a prosthetic leg” is not enough information. The engineer must know whether the leg is meant for walking, running, or another activity. A prosthetic designed for running needs to be lightweight, flexible, and able to handle the strong forces produced when someone runs. These needs are called criteria, which are the requirements a solution must meet. Engineers often make criteria measurable. Instead of saying “the prosthetic should be light,” they might set a goal that the leg must weigh less than 1.5 kilograms.
Engineers also consider constraints, which are the limits they must work within. Constraints may include cost, safety, the materials available, and environmental or social impacts. For a prosthetic leg, the materials must be safe, affordable, and strong enough to support the user. Sometimes engineers must make trade-offs, which means choosing one benefit over another. For example, a very lightweight material might be more expensive, so engineers must decide whether the extra cost is worth the improved performance.
Once engineers have defined the problem and identified criteria and constraints, they begin brainstorming possible solutions. Brainstorming is a creative process where all ideas are considered, even unusual ones, because unexpected ideas can lead to innovative results. Engineers then compare their ideas and choose the most promising ones to test. They build prototypes, or test models, and may also use computer simulations to predict how their design will perform. Often, they start with small-scale models before building a full-size version.
Engineering is an iterative process, meaning engineers repeat the design steps again and again. They test, learn from mistakes, make improvements, and sometimes start over if the design does not work as expected. Failure is not the end of engineering — it is an important part of learning what works and what needs to change. Through this cycle of testing and refining, engineers eventually create the best possible solution to the problem.
Part 2
Stop n' Jot
(5 min)
Criteria: The specific requirements a solution must meet to be considered successful. Criteria describe what a design has to do or be able to perform in order to solve the problem well. If a solution meets its criteria, it means it works the way it is supposed to and achieves its goal.
Examples of Criteria:
A prosthetic leg must be lightweight so the person can move easily.
A water filter must remove dirt and bacteria so the water is safe to drink.
A backpack must be strong enough to hold school supplies without ripping.
Constraints: the limits or restrictions that engineers must work within when creating a solution. These can include things like the amount of money available, the materials they can use, the time they have, safety rules, or environmental impacts.
Examples of Constraints:
A school garden project has a limited budget, so students can only buy certain seeds and tools.
A bridge design must use materials that are strong and safe, even if other materials might look cooler.
A science project must be finished by the deadline, so students can’t choose a design that takes too long.
Part 3:
Evaluate solutions for the restoration of coral reef habitats.
(5 min)
Coral reefs provide ocean habitats and are important for tourism. Many natural reefs have lost coral growth and biodiversity as a result ofacid rain, pollution, and increasing ocean temperatures. Artificial reefs are important to encourage new coral growth and restore reef habitats. Many materials have been tested as the base for coral growth.
Use the slide show below to research each material and gather the information needed to complete your decision matrix sheet.
REMEMBER TO LOOK AT THE BEFORE AND AFTER PICTURES OF THE ARTIFICAL CORAL REEF
Part 4:
Summary Report
(5 min)
After completing your criteria chart and scoring each material, write one paragraph explaining which artificial coral reef material — steel-hulled vessel, used tires, or concrete — you think is the best choice.
In your paragraph, make sure to: