Requirements, model and guided practice
Requirements and predictions
A performance criterion states what a design must achieve. A constraint limits resources, size or procedure. A prediction is a testable expectation, not a measured outcome. We evaluate complete sleeves here; changing two sleeve features does not isolate the effect of one.
100 g, start 10°C, room 22°C, 15 min. Final ≤16°C in EVERY trial; ≤4 tokens; ≤15 mm added thickness. Covered liquid water; cups/lids, mass, starting temperature, duration, exposure and reading procedure match within and across trials. Surroundings stay at the stated room temperature. No ice, phase change, active heating/cooling, direct sunlight or meaningful evaporative cooling. Each trial uses fresh samples. Accuracy is not supplied.
Supplied design record
Constructed teaching data: these values were invented for this activity, not collected in an experiment.
Design | Tokens | Added mm | Trial 1 final °C | Trial 2 final °C | Trial 3 final °C |
|---|---|---|---|---|---|
H | 3 | 12 | 16 | 16 | 16 |
1. Identify the performance criterion and the two resource/size constraints. Does H meet every nominal requirement? Show each check.
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2. H warms from 10°C to 16°C. Does it cool the water or stop all transfer? Classify “sealing its gap may reduce warming” as a prediction or an observed result. What matched test would investigate that prediction?
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Intended for middle school. Prerequisites: read °C/time, compare changes, consider trials and conditions. Paper and pencil only. Tokens are fictional resource units. Respond in connected prose, orally while pointing to data, or with a labeled representation. Clarify the question, table access, vocabulary and response mode before choosing a reteach. Sparse language can express adequate reasoning.
Check the complete brief
Question: Which designs meet the brief, and how could a teacher choose between feasible designs? A nominal pass concerns these supplied records, not a guarantee.
100 g, start 10°C, room 22°C, 20 min. Final ≤15.5°C in EVERY trial; ≤8 tokens; ≤20 mm added thickness. Covered liquid water; cups/lids, mass, starting temperature, duration, exposure and reading procedure match within and across trials. Surroundings stay at the stated room temperature. No ice, phase change, active heating/cooling, direct sunlight or meaningful evaporative cooling. Each trial uses fresh samples. Accuracy is not supplied.
Supplied design record
Constructed teaching data: these values were invented for this activity, not collected in an experiment.
Design | Tokens | Added mm | Trial 1 final °C | Trial 2 final °C | Trial 3 final °C |
|---|---|---|---|---|---|
A | 5 | 18 | 15 | 15.5 | 15 |
B | 8 | 20 | 14 | 14.5 | 14 |
C | 9 | 18 | 13.5 | 14 | 13.5 |
D | 6 | 24 | 14.5 | 15 | 14.5 |
1. For each design, check all three final readings, tokens and thickness. List every feasible design; record why each other design fails.
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2. Choose a feasible design and name a priority that makes your choice reasonable. Compare its resource use and thermal result with the other feasible design. State one limitation.
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A decision needs a priority
100 g, start 12°C, room 24°C, 18 min. Final ≤17°C in EVERY trial; ≤6 tokens; ≤18 mm added thickness. Covered liquid water; cups/lids, mass, starting temperature, duration, exposure and reading procedure match within and across trials. Surroundings stay at the stated room temperature. No ice, phase change, active heating/cooling, direct sunlight or meaningful evaporative cooling. Each trial uses fresh samples. Accuracy is not supplied.
Supplied design record
Constructed teaching data: these values were invented for this activity, not collected in an experiment.
Design | Tokens | Added mm | Trial 1 final °C | Trial 2 final °C | Trial 3 final °C |
|---|---|---|---|---|---|
E | 4 | 12 | 16 | 16.5 | 16 |
F | 6 | 18 | 15 | 15.5 | 15 |
G | 5 | 15 | 16 | 17.5 | 16 |
1. Identify all feasible designs. A fictional response says “G is fine because its average is under 17°C.” Evaluate that response against the actual all-trials rule.
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2. Choose between feasible designs. Explain a genuine tradeoff using at least two matched comparisons. What scientific idea helps explain why all these samples warm?
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A lower final reading can be relevant when starts and intervals match; it is not a universal decision rule. A difference in displayed readings is not proof of a reliable advantage.