| When | Change | Evidence | Session |
|---|---|---|---|
| 2026-10-20 | Secure → Secure | 19 Oct: club tree 40 -> 24 girls/16 boys -> walk/cycle, all three missing boxes right (3/3) with working; say-back of the branch rule 'i don't know'; stopped before independent trees. | session 119 |
| 2026-09-15 | Secure → Secure | audit: bar met in session 24 — drawn, photographed frequency tree with counts only, all six numbers correct on third asking; confirmed secure. | standalone |
| 2026-09-15 | Secure → Secure | 15 Sep starter: drawn FREQUENCY tree (80 people, 35 men, 20 men with dogs, 30 women with dogs), photographed. Counts only, no fractions: 35/45, 20/15, 30/15, every pair summing to the box before it. Third asking; the probability-tree substitution of 10 and 12 Sep did not recur. | session 24 |
| 2026-09-14 | Secure → Secure | 12 Sep starter: asked for a drawn frequency tree, produced a correct probability tree instead — all counts right and the answer correct, but fractions on branches rather than counts in boxes. Four consecutive probability trees appear to have made it automatic. | session 23 |
| 2026-09-11 | Secure → Secure | 10 Sep: drawn-tree check (5 black, 3 white socks, no replacement), photographed handwritten work. Tree drawn correctly — six branch probabilities labelled, pairs summing to 1, second-pick denominators all 7, ends labelled BB/BW/WB/WW. All three probabilities correct, sum-to-1 check applied, one-of-each routes added unprompted. Closes the loose end holding this at developing: the write-into-the-boxes habit is now evidenced. | standalone |
| 2026-09-10 | Developing → Secure | 10 Sep: drawn tree photographed — first handwritten work seen. Tree fully correct (5 black, 3 white, no replacement): both first-pick fractions, all four second-pick, each pair summing to 1, all six second denominators 7, ends labelled BB BW WB WW. 20/56, 6/56, 30/56 right, sum-to-1 check unprompted. Closes the loose end open since 2 Sep: the write-into-the-boxes habit is evidenced, not assumed. She can now photograph work, so drawn diagrams and timed papers can be marked. | standalone |
| 2026-09-07 | Developing → Developing | 7 Sep starter: gym frequency tree (120 people) all four boxes correct, answer 35, unaided. Third correct tree across three separate sittings. | session 7 |
| 2026-09-07 | Developing → Developing | 4 Sep starter: swimming frequency tree (200 people) correct and unaided, two days after teaching. Corroborates the 4/4 exit ticket but is not a spaced check. | session 6 |
| 2026-09-03 | Gap → Developing | Taught 2 Sep from a standing start. Guided example completed unprompted; practice Q1 tree + 7/40 correct; Q2/Q3 trees correct but part (b) unsimplified. Exit ticket (garage, 150 cars) 4/4 independent, all simplified, incl. P(failed car was petrol)=22/35. Taught and tested in the same session, so developing rather than secure per the N4/N10/N15 precedent. | session 2 |
No marked question has been recorded against this topic yet.