IB Diploma Programme History HL (first assessment 2020; current guide). This topic equips the INTERNAL ASSESSMENT — the historical investigation 历史探究: an 2 000-word piece of original historical research on a subject of the student's choosing, worth 20% at HL and SL alike. It is marked against six criteria, and this handout walks each: choosing and focusing a question, planning the research, selecting and evaluating sources, organising the evidence, analysing and concluding, and reflecting on the method — then the sources-and-referencing craft the whole thing stands on. The worked example is original and carried through every section.

Must-know for the investigation:

The question 问题 makes or breaks the investigation. A good one is NARROW (a person, a decision, an event, a policy — not “a war”), ANSWERABLE (the evidence exists and is accessible to a student) and NON-TRIVIAL (historians actually disagree, or the answer is not in the textbook). Compare: “Why did the League of Nations fail?” (too broad, narrative) against “How far was the Hoare–Laval Pact (1935) the decisive blow to League credibility?” (a decision, a date, a debatable “how far”). The The research plan 研究计划 states the question, the proposed method (which kinds of sources, which archives or editions) and a mini-bibliography — a plan, not a straightjacket: it is expected to evolve.

The research plan criterion also rewards a reasoned CHOICE of topic: personal interest, resource access and a genuine historiography 史学辩论. The classic failure is the biography-report: a life story retold with no question. Every step of the investigation answers back to the question — if a source or paragraph does not serve it, it goes.

The SOURCE-WORK is the investigation's heart: a broad, relevant and precise set of sources: primary sources 一手史料 where possible (documents, speeches, statistics, memoirs), secondary sources 二手史料 for context and debate (monographs, journal articles, reputable reference) — and then, crucially, TWO sources evaluated IN DEPTH with OPVL from topic 01: origin and purpose as handles, value and limitation RELATIVE TO THE INVESTIGATION'S QUESTION. A cabinet minute is valuable for ministers' real positions and limited for what happened in the room next door; a retrospective memoir is valuable for self-justification unmasked and limited for the sequence of events.

EVIDENCE is then organised to the argument, not to the narrative: grouped by THEME (each cluster serving one leg of the answer), with the sources cross-checked for corroboration 相互印证 and contradiction are both findings. Citation runs in-text (author, page) with a full bibliography; the apparatus criterion is consistency, not any single convention.

Analysis 分析 is argument: each thematic section argues its leg with evidence, weighs the counter-case, and hands on to the next — the structure criterion rewards an investigation that is ORGANISED AROUND A THESIS, with signposted sections and no narrative dead-ends. The CONCLUSION answers the question directly, states the judgement's grounds, and — the reflection 反思 criterion — OWNS ITS LIMITS: which sources were unavailable, whose voice is missing, what the investigation could not settle and why. Reflection is methodological, not confessional: what the evidence allowed and forbade.

Worked example. Question: “How far was the Hoare–Laval Pact (December 1935) the decisive blow to League credibility?” Plan: British and French cabinet records in published collections, the Contemporary press, and the historiography from 1936 to the present. Two deep sources: the pact's published text (origin: a Franco-British proposal leaked to the press; value: shows exactly what was conceded to Italy; limitation: a proposal, never a policy) and a leading article in “The Times” (origin: the newspaper of the British establishment; purpose: to rescue the government's policy; value: evidence of elite opinion in real time; limitation: political interest). Analysis: the pact followed Manchuria and preceded the Rhine remilitarisation — the thematic sections weigh concession as pattern against structure. Conclusion: the pact was decisive less for its terms than for its LEAK and withdrawal — credibility destroyed by its own authors — with the reflection noting the closed French archives and the pro-League bias of much historiography.

• Question narrow, answerable, non-trivial; the plan states question, method and a mini-bibliography (criteria 1–2).
• Source set broad, relevant, precise; primary where possible; TWO sources evaluated in depth with OPVL relative to the question (criteria 2–3).
• Evidence organised by theme to serve the thesis; corroboration and contradiction both reported (criterion 4).
• Analysis argues, weighs and signposts; the conclusion answers directly and owns its limits methodologically (criteria 4–5).
• In-text citation with a complete, consistent bibliography (criterion 6).
• The worked Hoare–Laval example's question, two deep sources and conclusion understood (all).

Boundary notes: 2 000 words for the body (plan, sources and bibliography excluded), marked against six criteria totalling 34; the word discipline is real — the reflection and analysis criteria reward precision, not padding. The worked example is original.