# New information · after first collection

Each page below is released only after its matching first response has been captured. Keep first and later work separately labelled. Review your conclusion; retaining an already careful statement is a valid decision when you explain why.


## F later page · The missing conditions

### Complete later source F

F's first geometric model used edges 3 mm and 6 mm and an imposed layer 0.5 mm deep at 2 minutes. Those dimensions and layer values remain unchanged. For this supplied interval, the layer starts at depth d_start = 0 mm when t_start = 0 min. Average front speed = Δdepth/Δtime = (d_end − d_start)/(t_end − t_start). This is the model's interval average, not a constant future speed, intrinsic diffusion coefficient or molecular flux.

The separate endpoint-time file lists A: 40, 44, 48 s and B: 88, 92, 96 s, with the same stated material, external solution and endpoint rule. Additional model-plan notes now state that A's temperature was set at 20°C and B's at 30°C, and stirring was not standardised. No actual experiment or learner investigation has occurred.

### Complete later task F

Review the endpoint-time conclusion in a second response. State whether you **keep** an already cautious claim or **revise** an overstatement, and explain why. Give the numerical comparison that remains valid, identify the temperature/stirring confounds, and describe an improved size comparison with a defined dependent measure and independent repeats. Name one geometric result that remains unchanged. Do not claim the notes prove the entire time difference is caused by temperature, stirring or size.