Start here: choose a route
Target: use matched fresh trials to compare thermal protectors, change a design, and revise a claim. Intended for Grade 6; relevant standards are in the Grades 6–8 band.
Practical route
Work under teacher supervision. Read the design brief through instruments and trial order. Record your phase’s instrument checks at instrument-check record. Run three first comparisons using the first-comparison trial 1–3 record forms. Compare results at compare the first trials. Read commit to a redesign and run three retests using the retest trial 1–3 record forms; finish the Reassess the Redesign and Evidence and Explanation tasks.
Supplied-data route
No equipment is needed. Read the brief and procedure, then use supplied first-comparison record and supplied redesign/retest record, which are fictional constructed records. Complete compare the first trials, commit to a redesign, reassess the redesign, evidence and explanation and a fresh later check. These records are not measurements from this class.
Ways to respond
Write, dictate, explain orally to a recorder, or use a labeled sketch/table. Give the same quantities, comparison conditions and evidence in any format. Graph drawing is optional.
Water is not for drinking. Keep cups in spill trays. Do not heat, cut, puncture or modify equipment. Tell the teacher about spills, leaks, damaged equipment or an unstable cup.
the design brief
Design a removable dry sleeve that may slow the warming of 150 mL of cool water in a covered plastic cup for 10 minutes in a classroom. This is a classroom comparison; it makes no promise about refrigeration, food, medicines or a particular final temperature.
The original sleeve uses one supplied 26 cm × 6 cm felt sheet, at most 3 mm thick. Baseline bare cup has no sleeve. The redesigned sleeve may use at most two supplied sheets total and at most 30 cm of tape. Its footprint must fit within a 12 cm diameter circle; its height must be at most 9 cm. Do not cover the base, top cover, probe slot or display.
Performance aim: look for less warming than the identified reference in comparable trials. A small or inconsistent difference can leave the result inconclusive. There is no numeric thermal pass mark.
1.Name the performance aim and three resource/size constraints. What result would leave the thermal claim inconclusive?
2.Predict how original sleeve might compare with bare cup. Explain why water might still warm in either cup.
run a matched pair
Use two suitable non-glass liquid probes with 0.1 °C displays, checked by the teacher for water immersion, temperature range and response instructions. Display steps do not establish accuracy. A separate classroom instrument records room air at cup height.
Standard conditions: room air 20–24 °C; common gently mixed cool-water batch 12–14 °C. Measure 150 mL into each cup using the same marked measure, within 2 mL. No ice goes into cups. Record the actual conditions.
Put probes at the marked depth and covers in place. Wait for the teacher-checked response interval (at least 60 seconds). Read both. Starts must differ by no more than 0.5 °C, both be 12–14 °C, and room must be at least 6 °C warmer. If not, keep the readings, mark a failed start, and ask for a fresh matched pair.
When both starts qualify, record both 0-minute readings and the actual clock time; start the timer. Record both probes at 5 and 10 minutes, within 15 seconds of each other and the target time. Record actual time if late. Keep probes in place; do not stir, move cups, lift covers or handle sleeves during a run.
Record room air at 0 and 10 minutes, missing readings, spills, movement and wet sleeves. A room shift over 1 °C, a missing 0/10 reading or a changed procedure flags an inconclusive comparison; retain it and repeat with fresh water if time permits.
After each run, retain the reading sheet. Teacher drains cups, checks sleeve dryness, and conditions cup interiors with 150 mL room-temperature water for 5 minutes. Drain and dry interiors before fresh cool water. Keep sleeves assembled and dry between runs; log any rebuild. Three timepoints are ONE trial. Three trials require three fresh water pairs.
instruments and trial order
Before each phase, the teacher places probes A and B together in stirred common water, first at room-water temperature and then at cool-batch temperature. Hold equal immersion depths without contact. Wait the maker’s response interval and at least 60 seconds; then read twice 30 seconds apart. Each probe must change no more than 0.2 °C between these readings and their displayed readings must differ no more than 0.5 °C. If not met within 2 minutes after the minimum response interval, replace/check equipment or use supplied data. Record all readings.
This is a consistency/response check, not calibration or proof of accuracy. Do not silently correct readings by subtracting an assumed offset. Repeat the check after the phase; a new disagreement flags possible drift.
First comparison order: F1: bare cup left/A, original sleeve right/B. F2: bare cup right/B, original sleeve left/A. F3: bare cup left/A, original sleeve right/B. Labels follow cups, not position. Teacher moves empty cups and swaps probes between trials, never during a run. This reduces a one-position or one-probe explanation but three trials do not perfectly balance everything.
1.A reads 13.0 °C and B reads 13.7 °C in the same mixed water after settling. Should the pair start? What does a 0.1 °C display tell you?
2.Why swap positions/probes between fresh trials? Why are 0, 5 and 10 minutes not three independent trials?
supplied first-comparison record
CONSTRUCTED FICTIONAL RECORDS. Constructed for analysis; no physical run or computational simulation produced these values.
Shared conditions: identical described cups/covers, 150 mL each, dry one-sheet original sleeve, probes as scheduled, minimum response 60 s. Fictional consistency checks: room A/B22.0/22.1 then 22.0/22.1 °C; cool 13.0/13.1 then 13.0/13.1 °C before and after phase. No spills or movement. Starts/clock/room readings appear below; date: fictional Day 1.
F1 bare cup left/A; original sleeve right/B. F2 bare cup right/B; original sleeve left/A. F3 bare cup left/A; original sleeve right/B. Each run used fresh water after the stated room-water reset.
Constructed teaching data: these values were invented for this activity, not collected in an experiment. Not computationally simulated.
| Minute | Clock | Reference °C | Prototype °C | Room °C |
|---|---|---|---|---|
| 0 | 09:00 | 13.0 | 13.1 | 22.0 |
| 5 | 09:05 | 14.6 | 14.3 | — |
| 10 | 09:10 | 16.0 | 15.3 | 22.2 |
Constructed teaching data: these values were invented for this activity, not collected in an experiment. Not computationally simulated.
| Minute | Clock | Reference °C | Prototype °C | Room °C |
|---|---|---|---|---|
| 0 | 09:20 | 13.2 | 13.0 | 22.1 |
| 5 | 09:25 | 14.9 | 14.3 | — |
| 10 | 09:30 | 16.4 | 15.4 | 22.2 |
Constructed teaching data: these values were invented for this activity, not collected in an experiment. Not computationally simulated.
| Minute | Clock | Reference °C | Prototype °C | Room °C |
|---|---|---|---|---|
| 0 | 09:40 | 12.9 | 13.0 | 22.2 |
| 5 | 09:45 | 14.5 | 14.2 | — |
| 10 | 09:50 | 16.0 | 15.3 | 22.2 |
compare the first trials
Use your F1–F3 records, or the constructed first-comparison records in the supplied first-comparison record. Temperature rise = 10-minute reading minus 0-minute reading. For each usable pair, compare the two rises; a smaller rise means less warming during that interval.
1.Make a table listing each run ID, reference rise, original sleeve rise and the difference (reference rise minus original sleeve rise). Include flags; do not combine flawed and usable trials silently.
2.Make a bounded claim using all three pairs. Identify one limit. You may use a table instead of a graph.
3.Would this comparison show that felt alone caused the difference? State what is compared and one further test.
commit to a redesign
Retest redesigned sleeve AGAINST original sleeve, the original one-sheet dry felt prototype, not against bare cup and not against an old reading. Keep original sleeve assembled and dry. Build redesigned sleeve on the third identical cup. redesigned sleeve may have one or two supplied sheets; total ≤30 cm tape, footprint ≤12 cm diameter, height ≤9 cm. Keep base/top/slot exposed. Teacher checks stability and probe placement.
Use the fresh-pair method and consistency check on the Instruments and Trial Order page. R1: original sleeve left/A, redesigned sleeve right/B; R2: original sleeve right/B, redesigned sleeve left/A; R3: original sleeve left/A, redesigned sleeve right/B. Preserve original sleeve as the concurrent reference. Keep redesigned sleeve assembled between runs; log any change.
1.Before seeing retest results, specify redesigned sleeve’s materials, dimensions and tape total. State your prediction, named reference and controls. If using supplied data, propose a design first; the later record is for the specified fictional redesigned sleeve, not your proposal.
2.Why is comparing today’s redesigned sleeve only with yesterday’s original sleeve endpoint weaker than concurrent retesting?
supplied redesign/retest record
CONSTRUCTED FICTIONAL RECORDS. These belong to the specified fictional redesigned sleeve, not to a learner’s unbuilt redesign.
Fictional redesigned sleeve: two 26 × 6 cm felt sheets, each 2 mm thick, 20 cm tape, footprint 9 cm diameter, height 8 cm; base/top/slot exposed. original sleeve reference: original single-sheet sleeve, unchanged. 150 mL each; identical cups/covers/probe placement; 60 s minimum response; fresh water and room-water reset each run. Day 2.
R1 original sleeve left/A, redesigned sleeve right/B; R2 original sleeve right/B, redesigned sleeve left/A; R3 original sleeve left/A, redesigned sleeve right/B. Fictional room/cool consistency readings before/after: same as Day 1. R2: a spill wet redesigned sleeve’s outer sleeve near 2 min; retained, flagged. Teacher replaced it with identical dry material for R3, recorded rebuild; R3 is not an unchanged uninterrupted sequence.
Constructed teaching data: these values were invented for this activity, not collected in an experiment. Not computationally simulated.
| Minute | Clock | Reference °C | Prototype °C | Room °C |
|---|---|---|---|---|
| 0 | 10:00 | 13.0 | 13.1 | 22.0 |
| 5 | 10:05 | 14.2 | 14.1 | — |
| 10 | 10:10 | 15.3 | 15.0 | 22.1 |
Constructed teaching data: these values were invented for this activity, not collected in an experiment. Not computationally simulated.
| Minute | Clock | Reference °C | Prototype °C | Room °C |
|---|---|---|---|---|
| 0 | 10:20 | 13.0 | 13.0 | 22.1 |
| 5 | 10:25 | 14.3 | 14.5 | — |
| 10 | 10:30 | 15.4 | 15.7 | 22.2 |
Constructed teaching data: these values were invented for this activity, not collected in an experiment. Not computationally simulated.
| Minute | Clock | Reference °C | Prototype °C | Room °C |
|---|---|---|---|---|
| 0 | 10:40 | 13.1 | 13.0 | 22.2 |
| 5 | 10:45 | 14.3 | 14.1 | — |
| 10 | 10:50 | 15.4 | 15.0 | 22.2 |
reassess the redesign
Use your R1–R3 records or supplied redesign/retest record. Keep the wet/changed/missing records visible. Compare redesigned sleeve with concurrent original sleeve, using the rises for each pair.
1.List each reference rise, redesign rise, difference and flag. Does the evidence support improvement? What should happen to an awkward result?
2.Check the redesign’s resource constraints. Write a revised claim and one exact next comparison.
evidence and explanation
1.Explain why a sleeve could slow warming without making the water colder or stopping all energy transfer. What can the temperature readings tell you?
2.Give two limits of your claim. Distinguish trial variation, display resolution and instrument accuracy.
3.Optional graph or table: represent one paired trial’s 0/5/10-minute readings. Label units and run ID; mark any anomaly. Explain one pattern using the representation.