- Look at the water bottle rocket test. Which is one variable students can change?
Answer: Amount of water put in the bottle before launch
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). Identifying variables helps you plan fair tests and understand what affects your results. In this scenario, students are testing how different factors affect a water bottle rocket's flight. The variables involved include amount of water, air pressure, and rocket height achieved. Choice A is correct because amount of water put in the bottle is indeed a variable in this situation: amount of water can be changed to test its effect on rocket height. Identifying this helps students test it systematically. Choice B represents confusing the result with a variable. Students who choose this may think the result is a variable when it's what you measure, not understanding difference between what to change and what to keep same. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Look at the design students made: Jamal built a marshmallow catapult with a spoon and rubber band. When he pulls the spoon back farther, the marshmallow goes farther, but the rubber band sometimes snaps. What is a failure point in this design?
Answer: The rubber band might snap when the spoon is pulled back
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). Identifying failure points before testing helps you strengthen weak spots or plan for problems. In this scenario, students are building and testing a marshmallow catapult with a spoon and rubber band. Potential failure points include the rubber band snapping during use. Choice A is correct because the rubber band might snap when the spoon is pulled back is a real way this design could fail: rubber band snapping would prevent catapult from launching. Recognizing this failure point helps students strengthen this part of the design. Choice B represents imagining problems that couldn't actually happen. Students who choose this may confuse realistic failures with impossible or magical events. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the test: Jamal launches marshmallows with a catapult. What is a failure point?
Answer: The rubber band might snap when pulled back (material failure).
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). In this scenario, Jamal is testing a catapult that launches marshmallows. Potential failure points include the rubber band snapping, joints coming loose, or the launching arm breaking. Choice B is correct because the rubber band snapping is a real way this design could fail: rubber bands can break when stretched too far or if they're old and brittle, which would prevent the catapult from launching anything. Recognizing this failure point helps students strengthen this part of the design by using stronger bands or not pulling too far. Choice A represents confusing results with failures. Students who choose this may not understand that going farther is a successful outcome, not something going wrong with the design. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the design. Amir's water bottle rocket uses taped-on fins. During flight, the fins sometimes fall off and the rocket spins down. What might go wrong during this test?
Answer: The fins might fall off, so the rocket spins and crashes
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). In this scenario, students are testing water bottle rockets where fins are attached with tape. Potential failure points include the fins falling off during flight, which causes the rocket to lose stability and spin. Choice A is correct because fins falling off is a real way this design could fail: without fins, the rocket loses aerodynamic stability and spins uncontrollably instead of flying straight. Recognizing this failure point helps students strengthen this part of the design with better attachment methods. Choice B represents imagining problems that couldn't actually happen. Students who choose this may not understand realistic failure modes - a rocket launched upward cannot dig underground tunnels. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the test. Chen built a catapult to launch marshmallows. He wants to test if spoon size matters, so he uses the same marshmallow weight and pulls back 4 inches each time. Sometimes the rubber band snaps when pulled. Where could this design break or stop working?
Answer: The rubber band could snap when the spoon is pulled back.
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). In this scenario, Chen is testing if spoon size matters in a catapult design for launching marshmallows, controlling marshmallow weight and pull-back distance. Potential failure points include the rubber band that provides the launching force. Choice B is correct because the rubber band snapping when pulled back is a real way this design could fail: rubber bands can wear out or be pulled beyond their elastic limit, and if it snaps, the catapult cannot launch anything, stopping the entire test. Choice A represents imagining problems that couldn't actually happen - students who choose this may have creative imaginations but don't recognize that marshmallows cannot transform into popcorn during a catapult launch. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed).
- Read about the test: Carlos tests catapults to see if spoon size matters. He must keep marshmallow weight, pull-back distance, and rubber band the same each time. What variables should students keep the same in this test?
Answer: Keep marshmallow weight and pull-back distance the same each try
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). Identifying variables helps you plan fair tests and understand what affects your results. In this scenario, students are testing if spoon size affects catapult performance. The variables involved include spoon size (test variable), marshmallow weight, pull-back distance, and rubber band (control variables). Choice B is correct because marshmallow weight and pull-back distance must be kept the same so differences come only from spoon size being tested. Identifying this helps students control it. Choice C represents confusing the result with a control variable. Students who choose this may think the result is a variable when it's what you measure. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the test: Emma tests if bigger wings make paper airplanes fly farther. She throws 3 times for each wing size. If she throws harder sometimes, results change. Which shows something that could make the test unfair?
Answer: Throwing with different force on different tries
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). Identifying variables helps you plan fair tests and understand what affects your results. In this scenario, students are testing if bigger wings make paper airplanes fly farther, throwing multiple times per size. The variables involved include wing size (test variable), throwing force (which if changed makes test unfair), and paper type (control variable). Choice C is correct because throwing with different force on different tries is indeed a variable in this situation: throwing force could change by accident making results unreliable. Identifying this helps students watch for it. Choice B represents confusing the test variable with something unfair. Students who choose this may not understand difference between what to change and what to keep same. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the bridge strength test. Where could this bridge design fail?
Answer: The middle could sag and sticks might snap under heavy books
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). Identifying failure points before testing helps you strengthen weak spots or plan for problems. In this scenario, students are building and testing a popsicle stick bridge for strength by adding weight. Potential failure points include sagging or snapping under load. Choice A is correct because the middle sagging and sticks snapping is a real way this design could fail: under heavy books, the structure could collapse due to weak support. Recognizing this failure point helps students strengthen this part of the design. Choice B represents imagining problems that couldn't actually happen. Students who choose this may confuse realistic failures with impossible ones like melting from sunlight. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the test: Sofia tests fertilizer on bean plants. Which is the test variable?
Answer: Type or amount of fertilizer added (the one thing changed).
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). In this scenario, Sofia is testing whether fertilizer helps bean plants grow. The variables involved include fertilizer type/amount (test variable), sunlight (control variable), plant height (result), and pot color (irrelevant factor). Choice B is correct because fertilizer type or amount is indeed the test variable in this situation: this is what Sofia deliberately changes to see its effect on plant growth, making it the one factor she's testing. Identifying this helps students understand what causes any differences in plant growth. Choice C represents confusing the result with a variable. Students who choose this may think the outcome (plant height) is something to change rather than something to measure after the test. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Look at the design students made: Keisha built a solar oven from a pizza box and foil. On cloudy days, the marshmallow does not melt, and opening the box lets heat out. Which is an uncontrolled variable (might change by accident)?
Answer: How sunny or cloudy the day is during the test
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). Identifying variables helps you plan fair tests and understand what affects your results. In this scenario, students are building and testing a solar oven from a pizza box and foil to melt marshmallows. The variables involved include weather conditions like sunniness (uncontrolled variable) and opening the box (which affects heat). Choice A is correct because how sunny or cloudy the day is during the test is indeed a variable in this situation: weather could change by accident making results unreliable. Identifying this helps students watch for it. Choice B represents confusing the result with a variable. Students who choose this may think the result is a variable when it's what you measure. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the design: Chen builds a popsicle-stick bridge. Where could it fail?
Answer: Joints might come apart if the glue is weak (material failure).
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). In this scenario, Chen is building a popsicle-stick bridge. Potential failure points include weak glue joints, sticks breaking under weight, or the bridge design being unbalanced. Choice A is correct because joints coming apart due to weak glue is a real way this design could fail: if the glue doesn't hold the sticks together strongly enough, the bridge will collapse when weight is added. Recognizing this failure point helps students strengthen this part of the design by using more glue or letting it dry longer. Choice C represents imagining impossible problems. Students who choose this may create unrealistic failure scenarios rather than identifying actual weak points in the design. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the design. Chen builds a popsicle-stick bridge and tests weights. Some glue joints are still wet, and the middle starts to sag. Where could this design break or stop working?
Answer: At weak glue joints that are not dry yet
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). In this scenario, students are building a popsicle-stick bridge and testing how much weight it can hold. Potential failure points include wet glue joints that haven't dried completely and the middle section that's already starting to sag. Choice A is correct because weak glue joints that are not dry yet is a real way this design could fail: wet glue doesn't have full strength, so joints could separate when weight is added. Recognizing this failure point helps students strengthen this part of the design by allowing proper drying time. Choice B represents confusing normal features with failures. Students who choose this may not recognize that being made of sticks is the intended design, not a weakness or failure point. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the solar oven test. What is one failure point in this design?
Answer: The box might not be sealed, so heat escapes
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). Identifying failure points before testing helps you strengthen weak spots or plan for problems. In this scenario, students are building a solar oven to heat a marshmallow using sunlight. Potential failure points include poor sealing or heat loss. Choice B is correct because the box not being sealed is a real way this design could fail: heat escaping would prevent the oven from warming up effectively. Recognizing this failure point helps students strengthen this part of the design. Choice A represents confusing normal features with failures. Students who choose this may not recognize specific weak points in the design and pick intended properties as problems. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the test. Carlos makes a water bottle rocket and wants to test fin design. He keeps the same bottle and uses 2 cups of water each launch. Sometimes the cap leaks air before he launches. What might go wrong during this test?
Answer: The rocket might leak air at the cap and not launch well.
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). In this scenario, Carlos is testing fin design on a water bottle rocket while keeping the bottle type and water amount constant. Potential failure points include the cap seal where air pressure builds up. Choice A is correct because the rocket leaking air at the cap is a real way this design could fail: if the cap doesn't seal properly, the pressurized air escapes before launch, reducing the launching force and making the rocket perform poorly regardless of fin design. Choice B represents imagining problems that couldn't actually happen - students who choose this may think rockets get hot from flying, but water bottle rockets don't generate heat that could melt plastic. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the bridge test. Which variable should students control to keep it fair?
Answer: Keep the number of books added each minute the same
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). Identifying variables helps you plan fair tests and understand what affects your results. In this scenario, students are testing bridge designs for strength by adding books. The variables involved include design pattern, number of books added, and sag amount. Choice B is correct because number of books added each minute is indeed a variable in this situation: it must be kept the same so differences come only from the design being tested. Identifying this helps students control it for consistency. Choice C represents confusing the result with a variable. Students who choose this may think the result is a variable when it's what you measure, not understanding difference between what to change and what to keep same. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the test. Carlos tests a catapult and changes spoon size. He keeps the marshmallow weight the same and pulls back 10 cm each time. What variables should students keep the same in this test?
Answer: Keep marshmallow weight and pull-back distance the same
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). In this scenario, students are testing how spoon size affects catapult performance. The variables involved include spoon size (test variable), marshmallow weight (control variable), and pull-back distance (control variable). Choice B is correct because marshmallow weight and pull-back distance are indeed variables in this situation: they must be kept the same so differences in launch distance come only from spoon size being tested. Identifying this helps students control these factors for a fair test. Choice C represents not understanding the difference between variables and results. Students who choose this may think they need to control the outcome (flight distance) when that's actually what varies based on the test variable. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the test: Maya tests wing size on paper airplanes. She uses the same paper, throws from the same spot indoors, and measures how far the nose lands each time. Which variable should students control to make the test fair?
Answer: Keep the throwing force the same each time (control variable)
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). Identifying variables helps you plan fair tests and understand what affects your results. In this scenario, students are testing how wing size affects paper airplane flight distance, using the same paper and throwing spot. The variables involved include wing size (test variable), throwing force (control variable), and flight distance (result). Choice B is correct because throwing force must be kept the same so differences come only from wing size being tested. Identifying this helps students control it. Choice A represents confusing the test variable with a control variable. Students who choose this may think the thing being tested should be kept the same instead of changed on purpose. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the test: Chen builds bridges from popsicle sticks and glue. He tests how many sticks make the bridge stronger by adding pennies. Some joints come apart if glue is weak. Where could this design break or stop working?
Answer: The bridge could fail where joints are poorly glued and come apart
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Failure points are places where a design could break, stop working, or have problems. These might be structural (parts break/snap), material-related (glue doesn't hold), design flaws (unstable, unbalanced), or testing issues (measured wrong). Identifying failure points before testing helps you strengthen weak spots or plan for problems. In this scenario, students are building and testing popsicle stick bridges by changing the number of sticks and adding pennies. Potential failure points include weak glue joints coming apart. Choice A is correct because the bridge could fail where joints are poorly glued and come apart is a real way this design could fail: weak glue means joints are unstable and bridge could collapse. Recognizing this failure point helps students strengthen this part of the design. Choice B represents imagining problems that couldn't actually happen. Students who choose this may confuse normal features with failures or pick impossible events. To help students: Before testing, ask "Where could this break? What could go wrong? What parts are weak?" Create list of potential problems, then test to see which actually happen. Practice categorizing: Structural (breaks/snaps), Material (glue fails/tape unsticks), Design flaw (unbalanced/unstable), Testing error (measured wrong/variables changed). Use sentence frame: "[Part] might [type of failure] because [reason]."
- Read about the test: Marcus tests paper planes outside. Which could make results unfair?
Answer: Wind changes during throws (uncontrolled environmental variable).
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). In this scenario, Marcus is testing paper planes outside. The variables involved include wind conditions (uncontrolled), paper type (control), folding technique (control), and measuring location (control). Choice A is correct because wind changing during throws is indeed an uncontrolled variable that makes results unfair: if some planes are thrown when it's calm and others when it's windy, differences in flight distance won't just be from the plane design but also from wind helping or hindering flight. Identifying this helps students recognize why indoor testing might be better or why multiple trials are needed. Choice B represents good testing practice. Students who choose this may confuse fair controls with unfair testing, not recognizing that using the same paper type is exactly what should be done to keep the test fair. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Practice identifying: In "Does fertilizer help plants grow?" Test variable = fertilizer amount; Controls = water, sunlight, pot size, seed type; Uncontrolled = temperature, forgetting to water. Ask: "What are we testing? What must stay the same? What could change by accident?"
- Read about the test. Marcus and Emma test a popsicle-stick bridge with books. They want to test if triangle supports are stronger than square supports. They keep the bridge width the same, but one bridge is much longer. Which shows something that could make the test unfair?
Answer: Using different bridge lengths could change how much it bends.
This question tests identifying variables and failure points in testing (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). Variables are factors that can change in an experiment or test. Some variables you change on purpose (test variable - what you're testing), some you keep the same (control variables - to make test fair), and some might change by accident (uncontrolled variables - things like weather). In this scenario, Marcus and Emma are testing whether triangle supports are stronger than square supports in popsicle-stick bridges. The variables involved include support shape (test variable), bridge width (control), and bridge length (which should be controlled but isn't). Choice A is correct because using different bridge lengths is indeed an uncontrolled variable in this situation: longer bridges naturally bend more under weight than shorter ones, so if one bridge is much longer, differences in book-holding capacity could be from length rather than support shape, making the test unfair. Choice C represents confusing the result with a test variable - students who choose this may think the number of books held should be changed on purpose, when it's actually what they measure to determine which support shape is stronger. To help students: Create three-column chart: "What We Change (Test Variable)," "What We Keep Same (Control Variables)," "What Might Change By Accident (Uncontrolled Variables)." Emphasize that all factors except the one being tested should stay the same.
