TL;DR SEAB’s Paper 3 “General marking points” spell out what examiners reward: full-precision readings, unit-labelled tables, best-fit lines that use most of the grid, and gradients taken with large triangles (SEAB 2026 Physics syllabus). Turn those bullets into automatic habits-check resolution before every reading, pre-draw table headers with quantity/unit, and rehearse gradient extraction with triangles spanning ≥50 % of the line. Log each practice run with a micro-audit so Planning/MMO/PDO/ACE evidence is baked into your workflow before the real Paper 3.
Quote metre-rule readings to 0.1 cm, vernier to 0.01 cm, micrometer to 0.001 cm, stopwatch to 0.1 s; jot the instrument resolution at the top of your data table before you start.
Table headings must carry quantity + unit (solidus format) and readings should be repeated when possible (same source).
Draft headers like Length, l / cm in pencil before entering data; schedule two quick repeat readings for each column.
Calculated quantities use the least number of significant figures from raw data; ratios as decimals to 2–3 s.f. (same source).
After every calculation, compare decimals with the weakest raw reading, then circle any answer with “too many” digits.
Graph axes must occupy most of the grid; points plotted with small crosses; straight-line gradients from large triangles (same source).
Sketch candidate axis scales before plotting; use a sharp pencil; mark triangle corners with coordinates and compute gradient to 2–3 s.f.
Read intercepts/gradients with accuracy better than half a square; balance points either side of the best-fit line (same source).
After drawing the line, count points above/below and adjust so they’re balanced; note the coordinates of triangle corners in your notebook.
2 | Pre-lab precision ritual ≤3 minutes
Resolution roll-call: Say the resolution out loud as you pick up each instrument (“Ruler 0.1 cm, stopwatch 0.1 s, balance 0.01 g”).\
Table skeleton: Draw table headers with quantity/unit; leave one empty column for processed values.\
Unit memo: Write the unit beside the equation you’ll apply (e.g. R = V / I (Ω)), so you never forget during the rush.\
Graph placeholder: On scrap paper, sketch the axis scales you expect to use-check they span at least 4 large squares each.
This ritual mirrors the mark-scheme priorities and takes less than 180 seconds once it becomes muscle memory.
3 | During the run: MMO + PDO checkpoints
After first reading: Confirm precision matches instrument resolution; if not, rewrite immediately.\
Mid-table audit: Tick a checkbox once you’ve logged a repeat reading for each variable.\
Before plotting: Count data points; ensure the chosen scale uses at least half the grid in both axes.\
Gradient extraction: Draw a large triangle ≥½thelinelength, label coordinates, compute gradient to 2–3 s.f., and record units (e.g. Gradient = 0.52 N cm⁻¹).\
Intercept note: If the task needs an intercept, read it with the same sub-square accuracy and note unit/meaning.
4 | Clean-up = ACE commentary fuel
Observation
ACE-ready note
Readings drifted upwards during IV sweep because the resistor heated.
“Temperature rise increased resistance (~3 % drift); allow cooling or use lower current to stabilise.”
Triangle corners fell on (0,0) and (8,4.2); gradient ≈ 0.53.
“Gradient = 0.53 ± 0.03; dominant uncertainty from voltage resolution (±0.1 V).”
Best-fit points: 4 above, 3 below.
“Line balanced—supports linear relationship within experimental scatter.”
Write these snippets next to your table before leaving the station-they translate directly into ACE sentences.
5 | Common pitfalls and how to auto-correct them
Slip
Fix-on-the-spot habit
Rounding raw readings (e.g. 22 °C instead of 22.0 °C).
Circle the reading; rewrite with full precision; annotate “thermometer 1 °C → record 0.5 °C increments.”
Missing units in column headers.
Keep a bright highlighter—if a header lacks / unit, highlight it until fixed.
Axes squeezed into a corner of the grid.
Before plotting, draw light guide lines showing mid-grid boundaries; adjust scale so plotted points cross those lines.
Small gradient triangles.
Set a minimum rule: hypotenuse must span ≥8 large squares vertically; if not, redraw.
6 | Gradient-drill circuit (10-minute practice)
Choose a published data set (e.g. t vs t² from free-fall, V vs I from a resistor).\
Plot on fresh graph paper using SEAB-approved scales.\
Draw two different best-fit lines (one intentionally poor).\
Compute gradients/intercepts with large triangles, noting units.\
Self-check: Did the “good” line balance points? Did your gradient triangle cover ≥½ of the line?\
Write a one-line ACE comment referencing gradient uncertainty.
Repeat weekly so the motion of drawing triangles and logging units becomes automatic.
7 | Paper 3 micro-habits audit
Paper 3 Micro Habit Checklist
-----------------------------
Station / Date:
[ ] Instrument resolutions stated before first reading
[ ] Table headers include quantity + unit
[ ] Repeat readings logged (✓ column)
[ ] Raw data sig. figs match least precise instrument
[ ] Graph axes use ≥50 % of grid in both directions
[ ] Gradient triangle spans ≥½ line; units recorded
[ ] Intercept (if needed) read with sub-square accuracy
[ ] ACE note written (uncertainty + improvement)
Photocopy and stick this on your lab book-tick every box before you dismantle the apparatus.
