Diagram Masterclass

Provenance (checked 2026-09-29): this document does no new primary-source extraction. It is a scope-check, not a teaching document, built by re-reading research/veridian/WEC14-verified-facts.md in full for every diagram/graph mention, content/veridian/curriculum/wec14/paper-anatomy.ts (the paper's own mark-mechanic reference page), and the technique-hub files that already touch diagrams — forge-error-pattern-tracker.md (EP7), forge-battle-card.md, codex-complete-worked-paper.md, forge-tariff-6-mark-analyse.md, codex-definitions-and-application-bank.md, forge-vocabulary-precision-list.md and signal-frequency-and-boundaries.md. Every claim below cites the file and line-level fact it comes from. Not affiliated with or endorsed by Pearson Edexcel. No likelihood percentage, no "confirmed in every series" claim, and no grade boundary appears below.

#WEC14 — Why There Is No "Diagram/Graph Masterclass" Here

Verdict: this document type does not apply to WEC14, and this file exists to say so rather than force one. Diagrams and graphs are real and recurring on this paper — but the mark schemes do not treat "the diagram itself" as a distinct, separately-creditable skill the way a Unit 1-style "draw and label a diagram" question would. What actually happens is narrower, and every real fact behind that conclusion is already written down elsewhere in this technique hub.

#1. Section A: diagrams are given, not drawn — and the mark is binary

Every diagram-related weak point on this paper is a reading task, not a construction task: students are shown a completed tariff diagram or Lorenz curve and must identify the correct labelled area or direction of shift inside a 1-mark multiple-choice question. There is no partial credit for "diagram accuracy" inside an MCQ — the mark is right or wrong on the answer letter, full stop. This is exactly what forge-error-pattern-tracker.md's EP7 ("Diagram/data-reading direction errors") already documents as its own named, recurring error pattern, with the real citations: October 2020 Q5 ("weakest amongst all the multiple-choice questions… unable to correctly deduce the area of tax revenue from the graph"), October 2021 Q4 (consumer-surplus area misread), January 2023 Q5 ("unable to accurately understand all the different areas"), and January 2025 Q6 (named the weakest MCQ of that series, steel-tariff diagram). codex-complete-worked-paper.md §"Question 4" already walks one of these MCQs in full, and forge-battle-card.md's tariff-diagram table and forge-vocabulary-precision-list.md's "a tariff diagram has (at least) four distinct areas, not one" entry already give the standing quick-reference facts. None of that is repeated here.

#2. Section B/C: diagrams help structure the answer, but are not separately marked

The single clearest primary-source statement on this is the October 2021 examiner report, already quoted in codex-complete-worked-paper.md §7: "Diagrams, even where not explicitly required, helped candidates who used them reach the top bands consistently, by adding structure the prose alone often lacked." Read that sentence carefully: it says diagrams are not required, and it credits them only indirectly, through the ordinary KAA/Evaluation marks the surrounding prose would have earned anyway. There is no line in any WEC14 mark scheme read for this course that allocates marks to "the diagram" as its own component separate from the Knowledge/Application/ Analysis/Evaluation the question already carries.

#3. The one confirmed exception — and why it still isn't a distinct skill

forge-tariff-6-mark-analyse.md §1 documents the one real case where a diagram had to be constructed for marks: January 2021's Section B 6-mark part required drawing a Lorenz curve, with 2 Knowledge marks for "correctly-labelled axes" and "correctly-labelled original Lorenz curve," 2 Application marks for reading the Gini values off Figure 1, and 2 Analysis marks for drawing the shifted curve and explaining it. That document is explicit that this is confirmed for one series only, not a recurring format. Just as importantly: the marks awarded are the same flat Knowledge-2/Application-2/Analysis-2 tariff every other 6-mark part on this paper uses — the diagram is the vehicle for those marks, not an additional "diagram" band layered on top. That case is already fully worked, with its own self-mark checklist, in that file; nothing here duplicates it.

#4. Where the actual diagram content already lives

Every diagram type this paper's curriculum teaches is already built, in full, in its home lesson — this document does not re-derive any of them:

And every real, verified fact about how diagrams behave in this paper's marking is already spread across, and cross-referenced between: forge-error-pattern-tracker.md (EP7 — the error pattern), forge-battle-card.md (the quick-reference table), codex-complete-worked-paper.md (a full worked MCQ plus the October 2021 examiner quote), forge-tariff-6-mark-analyse.md (the one construction exception), codex-definitions-and-application-bank.md (spec-referenced definitions of the four tariff areas and trade creation/diversion), and signal-frequency-and-boundaries.md (4.3.2.5 named in 5 of 14 series checked — Oct 2020, Oct 2021, Oct 2022 Q10 essay, Jan 2023, Jan 2025 steel-tariff MCQ).

#5. Honest limits

This is a scope-check, not new research. Nothing above is a new fact; every citation points to a document that already exists in this folder or in the curriculum. The one judgement call made here is the verdict itself — that WEC14's mark schemes do not create a distinct, separately- creditable "diagram/graph" skill category, as distinct from the ordinary Knowledge/Application/ Analysis/Evaluation marks a question already carries — and that judgement is stated with the exact evidence it rests on, not asserted without it. If a future series is found to require diagram construction with its own separate mark band (rather than folding diagram elements into the existing flat KAA tariff, as January 2021 did), that would be new evidence changing this verdict, and should be added to forge-tariff-6-mark-analyse.md §1 first, since that is where the one existing exception already lives — not forced into a masterclass here.