MS-ETS1-3: Combining the Best Features of Several Designs from Test Data
In plain English: MS-ETS1-3 is the NGSS middle school engineering performance expectation that asks students to analyze test data from several design solutions, find their similarities and differences, and identify the best characteristics of each that can be combined into a new solution that better meets the criteria for success. It is usually taught inside grades 6-8 science.
Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
Next Generation Science Standards · Disciplinary Core Idea: Engineering Design · Official standard
Engineers seldom build one design and stop. They test several design solutions (different designs that try to solve the same problem), compare the test data, and then combine the best parts into a new design. A characteristic or feature is one part or property of a design, such as a flat base or a longer wing. Recall that a criterion is something a design must do to succeed and a constraint is a limit, such as cost or time (MS-ETS1-1). In this lesson students organize test data in tables, find the mean (the sum of the trials divided by the number of trials) and the range (the largest value minus the smallest), and then look for similarities (what designs that did well have in common) and differences (what sets a strong design apart from a weak one). They link each result to the feature that caused it, choose the best feature of each design, check that the chosen features can work together, and test the combined design against the same criteria.
NGSS gives no Clarification Statement and no Assessment Boundary for MS-ETS1-3, so this lesson follows the wording of the performance expectation. Students do the practice of analyzing and interpreting data: every task gives them test results to compare and asks them to justify which features to combine. All test results, prices and times are invented for teaching and labeled as invented. The paper helicopter lab uses paper, scissors and paper clips only, and nobody climbs on chairs or desks.
Learning Objectives
By the end of this lesson, students will be able to:
Organize test data from several designs in a table and find each design's mean and range
Identify similarities and differences among the designs and link each result to the feature that caused it
Choose the best characteristic of each design, using the data and the criteria
Combine compatible features into a new design and predict how it will perform
Test the combined design against the same criteria and explain whether it better meets them
Prior Knowledge Required
Students should already be comfortable with:
Writing precise criteria and constraints for a design problem MS-ETS1-1
Evaluating competing designs against the criteria MS-ETS1-2
Fair tests that change one variable at a time (3-5-ETS1-3)
"Three friends each made a paper airplane. One flies the farthest, one flies the straightest and one is the easiest to fold. If you could build a fourth plane, how would you decide what to take from each one?"
Collect ideas. Students usually say "use the best parts of each." Ask: "How would you know which part made the plane fly far? What if two of the best parts cannot go on the same plane?" Tell students that today they will answer these questions with test data.
Direct Instruction15-20 minutes
From test data to a combined design. Define design solution, characteristic, mean, range, similarity and difference (see the overview). Then work through the phone amplifier problem in five steps, with Diagram 1 for the loudness data and Diagram 2 for the combination.
Invented test data: four passive phone amplifier designs
Design
Gain, 3 trials (dB)
Cost
Build time (min)
Steady when bumped?
A: paper cup horn
7, 9, 8
$0.20
5
No
B: cardboard tube
5, 7, 6
$0.00
3
Yes
C: tube with two cups
10, 12, 11
$0.60
12
No
D: wooden box
9, 9, 9
$4.00
30
Yes
Organize the data and find the means
A class designs passive phone amplifiers (no batteries) to make a phone louder for a group project. Each design is tested 3 times with a sound meter app 1 m away, recording how many decibels (dB, a unit of loudness) louder it is than the phone alone. Invented gains: A paper cup horn 7, 9, 8; B cardboard tube 5, 7, 6; C tube with two cups 10, 12, 11; D wooden box 9, 9, 9.
Result: Means: A (7 + 9 + 8) ÷ 3 = 8 dB; B 18 ÷ 3 = 6 dB; C 33 ÷ 3 = 11 dB; D 27 ÷ 3 = 9 dB. Ranges: A 2, B 2, C 2, D 0, so the trials agree closely and the differences between designs are larger than the spread within each one.
Check each design against the criteria
Criteria and constraints: a mean gain of at least 10 dB, a cost of no more than $1.00, a build time of no more than 15 minutes, and the device must stay steady when the desk is bumped. Invented results: A $0.20, 5 min, tips over; B $0.00, 3 min, steady; C $0.60, 12 min, rolls; D $4.00, 30 min, steady.
Result: A fails loudness (8 dB). B fails loudness (6 dB). C fails steadiness. D fails cost and build time. No design meets every criterion, but each one meets some.
Find similarities and differences, and link them to features
Look across the designs for what the strong results have in common.
Result: Similarity: A and C both have flared cup openings and are louder than the plain tube B (8 and 11 dB against 6 dB). Similarity: B and D both have flat bases, and both stay steady. Difference: C has two cups where A has one and gains 3 dB more. So the flared cups explain the loudness, and a flat base explains the steadiness.
Choose the best characteristics and combine them
The class keeps the best feature of each design that the data support and that fits the constraints.
Result: Keep C's two flared cups (the loudest) and add B's flat cardboard feet (steady and free). Drop D's heavy base, which works but costs too much. A's cup opening is the same idea as C's cups, done better in C. The two chosen features do not conflict: the feet go under the tube, the cups on its ends.
Test the combined design with the same tests
Design E is built and tested the same way. Invented gains: 10, 11, 12 dB. Cost $0.65, build time 14 minutes, steady when bumped.
Result: Mean gain (10 + 11 + 12) ÷ 3 = 11 dB, at least 10. Cost $0.65 ≤ $1.00, time 14 ≤ 15 minutes, steady. Design E meets all four criteria, which none of A-D did. Its trade-off: it is close to the 15-minute limit, so a build-time check with new builders is a sensible next test.
After each step, ask: "Which numbers support that? Could a different feature explain the result? Can these two features go on the same design?" Stress that a feature is worth copying only when the data link it to a good result, and that a combined design is a prediction until it is tested.
Guided Practice15 minutes
Pairs analyze invented data for three handle designs on a paper shopping bag. Criteria: the bag holds a mean of at least 6 kg before the handle tears, it scores at least 4 out of 5 for comfort (the mean of 5 testers), and the handle costs no more than $0.03 per bag.
Invented test data: three paper bag handle designs
Handle
Load before tearing, 3 trials (kg)
Comfort (out of 5)
Cost per bag
H1: twisted paper rope
6.0, 6.4, 6.2
4
$0.05
H2: flat folded strip
3.8, 4.2, 4.0
3
$0.01
H3: cut-out hole with a paper patch
7.1, 6.7, 6.9
2
$0.02
Find the mean load for each handle.
Make a table that marks which criteria each handle meets.
Write one similarity and one difference that the data show.
Choose the best characteristic of at least two handles and describe a combined handle. Explain why your chosen features can work together.
Describe the test you would run on the combined handle and the results that would show it is better.
Independent Practice10-15 minutes
Each student analyzes invented test data for three closures on a reusable snack bag. Criteria: it loses no more than 5 mL of water in 1 minute when a bag holding 100 mL is held upside down over a tub, a 6-year-old can open it in 4 seconds or less, and it still works after 50 trips through a dishwasher.
Invented test data: three snack bag closures
Closure
Water lost in 1 min (mL)
Opening time (s)
Works after 50 washes?
Z: zipper track
2
9
Yes
V: fold-over flap with hook-and-loop strip
15
2
Yes
B: button flap
30
6
No
Students write two similarities and two differences, name the best characteristic of each closure that is worth keeping (or explain why none is), propose a combined closure, and explain one way the combined features might interfere with each other.
Closure5 minutes
Exit ticket: "Why is a combined design only a prediction until it is tested? Give an example of two good features that might not work well together." Return to the warm-up and ask how the class would now choose what to take from each airplane.
Teacher note: MS-ETS1-2 evaluates competing designs against the criteria; MS-ETS1-3 goes one step further and builds a better design from the strongest parts. Repeating test, change and retest until the design is as good as it can be is the focus of MS-ETS1-4.
Differentiation Strategies
For Struggling Students
Give a criteria checklist table with one row per design and one column per criterion, to fill in with Yes or No before any comparison
Use sentence frames: "Designs ___ and ___ both have ___, and both ___." "Design ___ did better on ___ because it has ___."
Start with two designs and two criteria, then add one design at a time
For Advanced Students
Ask students to design a test that changes only one feature at a time to prove which feature caused a result
Have students find a combination that fails because of a conflict between features, and propose a way around it
Ask students to judge whether a difference between two means is large enough to trust, using the ranges
Assessment Guidance
What to Look For
Check that students compute means and ranges correctly and compare designs on every criterion, not only the headline number. Strong work names similarities and differences that are backed by numbers, links each good result to a specific feature, keeps only features that fit the constraints and do not conflict, and plans to test the combined design with the same tests. Watch for students who copy a feature that the data do not link to success, or who declare a combined design a success before testing it.
02
Classroom Activities
3 Activities
1
Paper Helicopter Test and Combine
40 minGroups of 3
Each group builds and tests four paper helicopter designs, pools the class data, then combines the best features into a fifth design and tests it. A paper helicopter is a strip of paper cut and folded into two wings on top and a body below; it spins as it falls.
Criteria and Designs
Criteria: a mean fall time of at least 2.0 s from 1.8 m (slow, so a seed or a sensor would drift gently), and landing inside a 50 cm target circle in at least 4 of 5 drops. Constraint: one sheet of copy paper per helicopter.
H1: long wings (10 cm), no paper clip. H2: short wings (6 cm), 1 paper clip on the body. H3: long wings (10 cm), 2 paper clips. H4: long, wide wings (10 cm long, 5 cm wide), 2 paper clips. H1, H2 and H3 have 3 cm wide wings.
Procedure
Tape a mark on the wall 1.8 m above the floor. One student holds the helicopter by the body with the wing tips level with the mark and lets go; nobody stands on a chair or desk. Center the target circle under the drop point.
Time each fall from release to the floor. Drop each design 5 times; record each time and whether it landed inside the circle.
Find the mean and range of the fall times for each design and enter them in the class table.
Sample Class Data (invented)
Mean fall times: H1 2.6 s, H2 1.4 s, H3 2.0 s, H4 2.4 s. Landings inside the circle: H1 1 of 5, H2 5 of 5, H3 4 of 5, H4 4 of 5. After the class combined features, H5 (long, wide wings like H4, with only 1 paper clip like H2) fell in a mean of 2.5 s and landed inside the circle 5 of 5 times.
Discussion Questions
What do the three designs with paper clips have in common in their landings? What does that suggest about the clip?
H1 and H3 have the same wings. What is the difference in their results, and which feature explains it?
Which designs meet both criteria? Did H5 do better than every design it borrowed from?
Modification for Distance Learning
Students build two designs at home, drop them from a marked height in a doorway, post their times to a shared table and use the class data to choose a combination.
2
Seed Tool Data Cards
20 minPairs
Pairs analyze invented test results for three hand tools that plant bean seeds in a school garden bed and design a combined tool on paper. Criteria: at least 12 seeds planted per minute, at least 90% of seeds at the right depth (2-3 cm) and at least 90% of seeds at the right spacing (10 cm apart, within 1 cm).
The Data Cards (invented)
Tube planter: a pipe pushed into the soil to a stop collar, with seeds dropped down the pipe. 8 seeds per minute; 95% at the right depth; 40% at the right spacing.
Seed tape: seeds glued 10 cm apart on a paper strip laid in a groove and covered. 20 seeds per minute; 60% at the right depth; 98% at the right spacing.
Spoon dropper: a long spoon that drops one seed at a time. 12 seeds per minute; 70% at the right depth; 55% at the right spacing.
Tasks
Mark which criteria each tool meets.
Find the best result on each criterion and the feature that explains it.
Sketch a combined tool and label which design each feature came from.
Write how you would test your tool to check all three criteria.
Discussion Questions
No tool meets all three criteria. Which tool meets the most, and which criteria does each tool miss?
The tube planter and the seed tape are each best at one thing. What feature gives each its strength?
A pair proposes "a seed tape laid in a groove made by a board with a 2.5 cm ridge." Which features does it combine, and what might go wrong?
Challenge Variation
Pairs build their combined tool from cardboard and tape, plant 20 dried beans in a tray of soil and measure depth and spacing with a ruler.
3
Combination Critique Cases
20 minGroups of 3-4
Four invented teams each combined features from earlier designs. Groups decide whether each combination is supported by the data, then rewrite the weak ones. Groups rotate every 5 minutes.
The 4 Cases (invented)
Case 1, chair foot pads: felt pads were the quietest (52 dB when the chair slid), rubber caps had the best grip (slid only 2 cm when pushed). The team made rubber caps with a felt bottom and tested them: 54 dB, slid 3 cm.
Case 2, birdhouses: the birdhouse used most often by birds was painted red and had a 3 cm entrance hole. The others were blue or green and had 4-5 cm holes. The team kept the red paint for its new design and used a 5 cm hole.
Case 3, field marker cones: the steadiest cone had a heavy, flat rubber base; the cone that stacked best was thin and hollow. The team proposed one cone with "the heavy base and the thin, nesting body."
Case 4, pencil cases: the team combined the biggest pocket from one design and the strongest zipper from another, then declared the new case "the best design" without testing it.
Discussion Questions
Only one case tested its combination and met both of its goals well. Which one, and how close did it come to the best single result on each criterion?
In Case 2, which feature do the data really point to, and why is the paint a weak choice?
In Case 3, what conflict do you see? Suggest a way to keep both strengths.
In Case 4, what should the team do before calling the case the best design?
Modification for Distance Learning
Post the cases as slides. Groups vote on whether each combination is supported, then rewrite the weak ones in breakout rooms.
03
Diagrams & Visual Aids
2 diagrams
Diagram 1: Mean Loudness Gain of Five Phone Amplifier Designs (Invented Data, to Scale)
Invented test data from the Direct Instruction example, drawn to scale. Each bar is the mean of 3 trials; the dashed line is the 10 dB criterion. Only Design C reaches it among the first four designs, and C fails on steadiness. Design E combines features of B and C.
Diagram 2: Which Characteristic Came from Which Design
The best characteristic of each design, the data that support it, and the two features that went into Design E. A feature is copied only when the data link it to a good result and it fits the constraints.
04
Homework Assignment
~30 min
MS-ETS1-3 Homework: Combining the Best Features
Directions: All test results are invented for practice. Show each mean and range. For every feature you choose, name the data that support it.
Part 1: Similarities and Differences (Problems 1-2)
Four balloon-powered cars were each run 3 times on the same hallway floor. Car A (wheels cut from old CDs, wide straw nozzle): 3.2, 3.6, 3.4 m, veered 40 cm off a straight line. Car B (bottle-cap wheels, narrow straw): 2.1, 2.3, 2.2 m, veered 5 cm. Car C (CD wheels, narrow straw): 2.8, 3.0, 2.9 m, veered 8 cm. Car D (bottle-cap wheels, wide straw): 2.6, 2.4, 2.8 m, veered 35 cm. (a) Find each car's mean distance. (b) What do the cars with CD wheels have in common? What do the cars with wide straws have in common? (c) The criteria are a mean of at least 3.0 m and a veer of no more than 15 cm. Does any car meet both? Which features would you try to combine, and what conflict must you solve?
Three straw rockets were each launched 5 times from the same squeeze-bottle launcher at the same angle. Rocket 1 (4 paper fins, paper nose): mean 5.0 m, landed within 1 m of the target 5 times. Rocket 2 (no fins, clay nose): mean 6.8 m, 1 time. Rocket 3 (2 fins, clay nose): mean 6.5 m, 3 times. The criteria are a mean of at least 6.0 m and at least 4 landings within 1 m. (a) Write one similarity and one difference that the data show. (b) Which feature seems to add distance, and which seems to add accuracy? (c) Describe a combined rocket and predict its results. Safety: never aim a rocket at a person.
Part 2: Choosing What to Combine (Problems 3-4)
Three whiteboard eraser designs were tested by erasing the same marker square with 3 strokes. Felt block: removed 70% of the ink, lasted 400 uses, cost $1.00. Microfiber pad: removed 95%, lasted 150 uses, cost $1.50. Foam sponge: removed 80%, lasted 60 uses, cost $0.50. Criteria: at least 90% removed, at least 300 uses, no more than $2.00. (a) Which criteria does each eraser meet? (b) Name the best characteristic of two of the erasers. (c) Describe a combined eraser and explain how you would test whether it meets all three criteria.
Three field marker cones were tested. Cone 1 (heavy, flat rubber base): stayed up in wind of 30 km/h, cannot stack. Cone 2 (thin, hollow plastic): blew over at 10 km/h, stacks 20 high in 40 cm. Cone 3 (hollow cone with a ring of sand-filled pockets around the bottom edge): stayed up at 25 km/h, stacks 20 high in 90 cm. Criteria: stays up at 25 km/h and 20 cones stack in no more than 60 cm. (a) Which criteria does each cone meet? (b) Why can't a team simply put Cone 1's base on Cone 2's body? (c) Suggest a combination that keeps the strengths of two cones without the conflict, and say what you would test first.
Part 3: Testing the Combination (Problems 5-6)
A team built spoon launchers that toss pom-poms at a target 2 m away. The longest arm threw farthest, and the stiffest spoon threw the most consistently. The team combined the longest arm with the stiffest spoon. In 5 trials the pom-poms landed 2.9, 3.1, 2.8, 3.2 and 3.0 m away. (a) Find the mean and range. (b) Did the combination do what the team wanted? Explain. (c) Why might two good features not work well together here, and what would you change and test next?
Three cardboard bookend designs were tested. Bookend X (wide base): held 12 books before sliding, did not tip when pushed. Bookend Y (rubber strip under the base): held 18 books, tipped when pushed. Bookend Z (L-shape with a tall back): held 9 books, did not tip, costs $0.80 more than X or Y. Criteria: holds at least 15 books and does not tip. (a) Make a table of which criteria each design meets. (b) Choose features to combine and justify each with data. (c) Write a test plan for the combined bookend: what you will measure, how many trials, and what results would show it better meets the criteria.
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
Data Analysis
Means, ranges and criteria checks correct for every design
One calculation or criteria-check error
Similarities and Differences
Names similarities and differences backed by numbers and links each to a feature
Lists similarities or differences without linking them to features
Combination
Chooses compatible features that the data support and that fit the constraints
Chooses features without data, or misses a conflict
Testing
Plans or interprets a test of the combined design with the same tests and criteria
Assumes the combination works without a test
05
Quiz: 20 Questions
Interactive, with answers
Instructions
All test results, prices and scores are invented. Your score updates as you answer, and Reset quiz clears everything so you or your students can try again. Short-answer questions show a model answer.
Multiple choice: pick an option to check it. Short answer: write your answer, then reveal the model answer.
0 of 20 answered · 0 correct
Question 1 of 20 · Multiple Choice
What is the main purpose of comparing test data from several design solutions in MS-ETS1-3?
Answer: B
The goal is to find the strongest characteristic of each design, using the data, so they can be combined into a new design that better meets the criteria. Choice A defends one design instead of learning from all of them. Choices C and D are not goals of the analysis.
Question 2 of 20 · Multiple Choice
A brake design for a marble ramp stopped a marble in 14 cm, 18 cm and 13 cm in three trials. What is the mean stopping distance?
Answer: C
Mean = (14 + 18 + 13) ÷ 3 = 45 ÷ 3 = 15 cm. Choice A is the middle value of the three, not the mean. Choice B is the sum before dividing, and choice D is the range (18 - 13).
Question 3 of 20 · Multiple Choice
Shelf bracket criteria: holds at least 3 kg and costs no more than $2. Results: P holds 4 kg, $2.50; Q holds 3 kg, $1.80; R holds 2 kg, $1.20; S holds 5 kg, $3.00. Which bracket meets both criteria?
Answer: B
Only Q holds at least 3 kg and costs no more than $2. Choices A and D are strong enough but cost too much, and choice C is cheap but holds only 2 kg.
Question 4 of 20 · Multiple Choice
A class tested six paper towers. The two tallest towers both used triangle braces between their legs; none of the other four had triangle braces. What similarity do the data show?
Answer: D
The two best results share one feature that the weaker designs lack, which suggests triangle braces help a tower stand tall. Choices A, B and C are not shown by these data.
Question 5 of 20 · Multiple Choice
Why should each design be tested several times instead of once?
Answer: A
Results change a little from trial to trial, so the mean of several trials is a fairer summary, and the range shows how much the results vary. Choice D picks the best trial, which hides the variation. Choices B and C are not reasons.
Question 6 of 20 · Multiple Choice
Two water-bottle holders are the same except that holder W has a rubber base. In 10 bumps, W slid 0 times and holder X slid 6 times. What can the team conclude?
Answer: C
Because the rubber base is the only difference, it is the feature that explains the difference in sliding. Choice B goes too far: rubber helped here, not everywhere. Choice D misses the one difference, and choice A is not shown by the data.
Question 7 of 20 · Multiple Choice
A helicopter design had fall times of 3.1 s, 2.5 s, 2.9 s and 2.7 s. What is the range?
Answer: A
Range = largest - smallest = 3.1 - 2.5 = 0.6 s. Choice B subtracts the last trial from the first (3.1 - 2.7) instead of the smallest value from the largest. Choice C is the mean, and choice D is the sum.
Question 8 of 20 · Multiple Choice
Design A is lightest because its walls are thin. Design B is strongest because its walls are thick. Why can't the team just combine "thin walls" and "thick walls"?
Answer: D
Thin and thick walls cannot both be true of the same wall, so the team must find another way to be both light and strong, such as thin walls with ribs. Choice A is too strong a claim, choice B is not a rule, and choice C contradicts the data.
Question 9 of 20 · Multiple Choice
A team has just built a new design that combines the best features of three earlier designs. What should it do next?
Answer: B
A combined design is only a prediction until it is tested, and the same tests make the comparison fair. Choice A skips the test. Choice C bends the criteria, and choice D throws away the evidence needed for comparison.
Question 10 of 20 · Multiple Choice
Two kick scooter designs differ in wheel size, deck length and handle height. Scooter 1 rolled farther. Which next test would best show whether wheel size caused the difference?
Answer: C
When designs differ in several ways, you cannot tell which feature caused a result. Changing only the wheels isolates that feature. Choice A changes the hill, choice B uses opinions, and choice D changes nothing that affects rolling.
Question 11 of 20 · Multiple Choice
The best original bag handle held a mean of 6.9 kg. A combined handle held 8.3 kg. By about what percent did the combined handle improve on the best original?
Answer: D
Improvement = (8.3 - 6.9) ÷ 6.9 = 1.4 ÷ 6.9 ≈ 0.20, about 20%. Choice A reads the 1.4 kg difference as a percent. Choice B divides by the new value, 8.3, instead of the original, and choice C reads the ratio 8.3 ÷ 6.9 ≈ 1.2 as the percent increase.
Question 12 of 20 · Multiple Choice
A team combined a wide wing from one glider with a heavy nose from another. Each feature helped on its own, but the combined glider dove into the floor. What is the best explanation?
Answer: A
Features can affect each other: a nose heavy enough for one wing can be too heavy for another, so the combination behaves differently from either part. Choices B and C throw out data that were fine, and choice D overstates one failure.
Question 13 of 20 · Multiple Choice
Which statement describes a difference between designs, based on test data?
Answer: B
A difference compares the designs on a measured result: one held 4 kg more. Choices A and D describe similarities, and choice C is an opinion, not test data.
Question 14 of 20 · Multiple Choice
Three umbrella drip trays were tested. Tray 1 caught all the drips but tipped easily. Tray 2 never tipped but overflowed. Tray 3 was the cheapest. Which plan best uses the data to start a combined design?
Answer: C
The data show Tray 1 is best at catching drips and Tray 2 is best at staying upright, so pairing those features targets both weaknesses. Choice A ignores two criteria. Choice B includes features that may conflict or add nothing, and choice D ignores what Tray 2 shows.
Question 15 of 20 · Short Answer
Three dustpans were tested on the same pile of crumbs. Dustpan 1 (rubber edge): picked up 95% of the crumbs, held 200 mL, did not stand up on its own. Dustpan 2 (metal edge): 80%, held 500 mL, stood up on its own. Dustpan 3 (plastic edge): 85%, held 450 mL, did not stand up. Write two similarities and two differences, and name the best characteristic of two dustpans.
Similarities: Dustpans 1 and 3 both cannot stand up on their own; Dustpans 2 and 3 both hold a lot (450-500 mL). Differences: Dustpan 1 picks up 10-15 percentage points more crumbs than the others; Dustpan 2 is the only one that stands up. Best characteristics: Dustpan 1's rubber edge (best pickup) and Dustpan 2's large, self-standing body (most capacity and storage). A combined dustpan could put a rubber edge on Dustpan 2's body.
Question 16 of 20 · Short Answer
Four string telephones were tested by a listener 10 m away who rated loudness from 1 to 5. Paper cups with cotton string: 2. Paper cups with fishing line: 4. Plastic cups with fishing line: 3. Plastic cups with cotton string: 1. Which string and which cup are best? Explain how the data show it.
Fishing line is the better string: with the same cups it scored higher (paper 4 vs 2; plastic 3 vs 1). Paper cups are the better cups: with the same string they scored higher (fishing line 4 vs 3; cotton 2 vs 1). Because each comparison changes only one feature, the data show the effect of each feature. The best combination, paper cups with fishing line, has already been tested and scored 4.
Question 17 of 20 · Short Answer
Four lunch-box latches were tested for how many times they could open and close before breaking (2 trials each). Latch A: 180, 220. Latch B: 450, 410. Latch C: 90, 110. Latch D: 300, 340. Latch A is the easiest to open and Latch B is the strongest. Find each mean and explain which two latches you would study for a combined design.
Means: A (180 + 220) ÷ 2 = 200; B (450 + 410) ÷ 2 = 430; C (90 + 110) ÷ 2 = 100; D (300 + 340) ÷ 2 = 320. Study B for its durability (the highest mean, more than twice A's) and A for its easy opening. A combined latch might use B's materials or hinge with A's opening shape; it must be tested for both durability and ease of opening.
Question 18 of 20 · Short Answer
A team combined the quietest chair pad (felt, 52 dB) with the best-gripping pad (rubber caps, slid 2 cm). The combined pad tested at 54 dB and slid 3 cm. Was the combination a success? Explain using the data.
Mostly yes. The combined pad is only 2 dB louder than the quietest pad and slides only 1 cm more than the best-gripping pad, so it is close to the best result on both criteria at once, while each original pad was good at only one. Whether it is a success depends on the criteria: if the class set limits such as "no louder than 55 dB" and "slides no more than 3 cm", it meets both.
Question 19 of 20 · Short Answer
A team wants to combine the fast pour of one watering-can spout with the gentle spray of another. Write a test plan for the combined spout: what to measure, how many trials, and what results would show it is better.
Sample: Measure (1) time to pour 1 L of water with a stopwatch and (2) how much soil the spray moves, for example the depth of the dent it makes in a tray of loose soil, using the same tests as for the original spouts. Run at least 3 trials of each and find the means. The combined spout is better if its pour time is close to the fast spout's and its soil dent is close to the gentle spout's, so that it meets both criteria where each original met one.
Question 20 of 20 · Short Answer
A student says, "We should just pick the design with the best total score and stop." Explain why MS-ETS1-3 asks students to look for the best characteristics of each design instead.
The design with the best total may still be weak on one criterion, and a weaker design may be the best on that criterion. By comparing the data feature by feature, the team can combine the strongest parts of several designs into a new one that meets more of the criteria than any single design did. The new design must then be tested, and the cycle can repeat.
0 of 20 answered · 0 correct
06
Frequently Asked Questions
10 Questions
What does MS-ETS1-3 mean?
MS-ETS1-3 asks students to analyze test data from several design solutions, find their similarities and differences, and identify the best characteristics of each that can be combined into a new solution that better meets the criteria. The code means Middle School, Engineering, Technology and Applications of Science, core idea 1 (Engineering Design), performance expectation 3.
What grade is MS-ETS1-3 taught in?
It is a grades 6-8 standard, usually taught inside a science unit with a design project, after students have defined criteria (MS-ETS1-1) and evaluated competing designs (MS-ETS1-2).
How is MS-ETS1-3 different from MS-ETS1-2?
MS-ETS1-2 asks how well each competing design meets the criteria, often with a decision matrix. MS-ETS1-3 goes further: it uses the test data to pick out the best feature of each design and combine those features into a new design.
What counts as a similarity or a difference in test data?
A similarity is something the designs share, especially something the best designs have in common, such as "both quiet chairs had soft rubber feet". A difference compares the designs on a measured result, such as "Design B ran 30 minutes longer than Design A". Both should be backed by numbers.
How do you know which feature caused a good result?
Compare designs that differ in only one feature, or run a new test that changes one feature at a time. When designs differ in many ways at once, a good result could come from any of them, so the link is only a guess until it is tested.
Can any two good features be combined?
No. Some features conflict, such as thin walls and thick walls, and some interact, so a combination can behave differently from either part. That is why the combined design must be tested with the same tests and criteria.
What math do students need for MS-ETS1-3?
Mostly means, ranges and simple percents, which students meet in grade 6 statistics (6.SP.B.5) and grade 7 percent work. Reading tables and bar graphs carefully matters as much as the arithmetic.
What are good classroom projects for MS-ETS1-3?
Projects with quick, repeatable tests work best: paper helicopters, balloon cars, straw rockets, string telephones and paper towers. Each team can test several designs in one period and combine features in the next.
How is MS-ETS1-3 assessed?
Students are given test results from several designs and asked to compare them, name the best characteristics with evidence, propose a combination and say how they would test it. A strong answer cites numbers and explains why the chosen features can work together.
How does MS-ETS1-3 connect to high school?
MS-ETS1-4 next asks students to use models to test and improve a design over several rounds. In high school, HS-ETS1-3 asks students to evaluate solutions to complex problems with prioritized criteria and trade-offs.
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Related Standards
5 standards
These standards connect to MS-ETS1-3: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
3-5-ETS1-3Prerequisite
Plan and carry out fair tests to find parts of a model or prototype to improve
Lesson coming soon
MS-ETS1-2Prerequisite
Evaluate competing design solutions with a systematic process against the criteria
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