Practical session 6: Assemble and run three first comparisons

Mentor Teaching · Teacher directions · 15 October 2026

Plan and prerequisites

75–95 minutes plus adult preparation; continue after trial 1 when needed. Planning estimate; adjust to the class.

Accurate decimal °C/time reading; calculate change; measure 150 mL; follow the matched-pair and probe-position procedure. Carry forward the preceding session evidence. The adult must check the current complete operational guide, equipment and room/water conditions before handling.

Print in this order

1. Practical first comparison: directions and blank trials

Give each independent or new-evidence file only at the stage described below. Keep answers with the teacher.

Teach and demonstrate

Use the current 6 October operational guide. Check stable matching cups/loose covers, suitable non-glass immersion probes, probe support/depth, spill tray, pre-cut felt/tape and a marked 150 mL measure. Water is not for drinking. Learners do not heat, cut, puncture or modify equipment. Model a blank reading-log entry; never invent experimental values.

Learner work and evidence

Follow all standard conditions printed with the student procedure: 150 mL within 2 mL; room 20–24 °C; common cool batch 12–14 °C; starts within 0.5 °C, both 12–14 °C, room at least 6 °C warmer. After the checked response interval (at least 60 seconds), record 0/5/10-minute readings, actual times, 0/10 room air and departures. Complete F1–F3 with three fresh pairs; three timepoints are one trial. Keep all readings.

Next decision and continuation

Complete pre/post-phase instrument checks and the printed probe/position alternation; display resolution is not accuracy. Retain failed starts and inconclusive trials. A room shift over 1 °C, missing 0/10 reading or changed procedure requires a flag, not invented correction. Between trials, the teacher drains, checks dry sleeves, conditions interiors with room-temperature water for 5 minutes, drains/dries and prepares fresh water. If stopping after F1, clean/store dry labelled sleeves and finish F2/F3 in another supervised block before redesign. No equipment homework.

Matching complete teacher key

Use the complete current 17-page operational teacher guide, including setup, procurement, conditions, worked records, first-comparison keys and cleanup. The selected student packet contains no constructed first-trial results.

Open the matching complete teacher guide

Access and interpretation

Offer oral, dictated, pointing or labelled responses when they show the same intended reasoning. Keep each task’s quantities, conditions and sources available. Allow extra response paper. A supplied-data explanation does not establish actual construction or testing.