IBDP (IB Diploma) Complete Mastery Guide: Subject Selection, TOK/EE, and Score Strategy Explained【2026 Edition】

The IB Diploma Programme (IB DP) is the final stage of the International Baccalaureate (IB) curriculum for ages 16–19. It comprises six subjects plus three core requirements (TOK/EE/CAS) completed over two years, and is one of the world's most rigorous high school curricula. Students are assessed out of a maximum of 45 points: six subjects (7 points each) plus core components (up to 3 points).

According to IBO official statistics from the May 2025 examination session, the global average was 30.58 points with an 81.26% pass rate. Approximately 202,000 candidates sat the examination, and only 4.68% (approximately 9,500 students) achieved 40 points or above.

The DP is demanding. However, "demanding" does not mean "impossible." With correct subject selection and time management, the DP becomes a conquerable "strategic game".

This article covers the DP's subject structure, decision criteria for Math AA versus AI, concrete strategies for TOK/EE/CAS, internal assessment (IA) preparation, a two-year timeline, and score design to achieve 40 points or above—everything you need to navigate the DP successfully.

For those wishing to understand the broader IB landscape (PYP/MYP/DP frameworks, authorized school lists, university progression, etc.), please refer to the following article.

DP Subject Structure—The Six Groups: Specific Subjects and Selection Strategy

In the DP, students select one subject from each of six subject groups and designate three subjects as HL (Higher Level) and three as SL (Standard Level). HL subjects have approximately 1.5 times the teaching hours of SL and require deeper conceptual understanding.

The Six Subject Groups and Key Subjects

Strengthening Science: Substituting for Group 6 (The Arts)

Group 6 (The Arts) can be replaced by selecting an additional subject from another group. For example, you can take two sciences: "Physics HL + Chemistry SL." This is common among medical school candidates (Chemistry HL + Biology SL) and engineering candidates (Physics HL + Chemistry SL).

Essential Principles for HL/SL Selection

Choose HL subjects based on university prerequisites, not on what you find "easiest." For instance, Oxford's medical program mandates Chemistry HL, and Cambridge's engineering program requires Math AA HL. Errors in HL/SL selection often go unnoticed until the application stage, and by then it is too late to correct them.

Math AA vs. Math AI—This Choice Determines Your Path

The most critical subject decision in the DP is mathematics. Math AA (Analysis and Approaches) and Math AI (Applications and Interpretation) may sound similar, but their content and university standing are entirely different.

Comparing the Two Mathematics Courses

Choosing AI simply because it "seems easier" is the most dangerous decision you can make. Top-tier medical, engineering, and economics programs almost universally mandate Math AA HL. When in doubt, choose AA—it is the safe choice.

Recommended Subject Combinations by Intended Major

Mastering the Core Requirements—TOK, EE, CAS: Why "Just 3 Points" Are Critical

Of the DP's 45 points, the core components (TOK + EE + CAS) contribute a maximum of 3 points. These "3 points" may seem insignificant, but securing these 3 points consistently is the key to breaking through the 40-point barrier. Additionally, failure to complete CAS results in a Diploma Not Awarded, regardless of subject scores.

TOK (Theory of Knowledge)—Three Strategies for High Scores

TOK is a philosophical course exploring "What is knowledge?" and is assessed through an essay (1,600 words) and an Exhibition.

Although "there is no single correct answer" in TOK, a clear framework for high-scoring essays definitely exists.

Strategy 1: Compare two or more Areas of Knowledge. For example, contrast "certainty in mathematics" with "the diversity of interpretation in history." Essays focused on only one area of knowledge tend to score lower.

Strategy 2: Use specific, concrete examples. Purely abstract arguments receive lower marks. Ground your discussion in actual scientific discoveries, historical events, or personal experience.

Strategy 3: Always include counterargument (counterclaim). Present opposing viewpoints to your thesis and then refute them. This structure is essential for an A-level grade. Essays presenting only one perspective typically cap out at a B.

EE (Extended Essay)—Topic Selection Determines 80% of Success

The EE is a 4,000-word academic paper that must meet university-level thesis standards. The most critical factor in EE success is selecting your research topic.

Essential Principle 1: Narrow your Research Question (RQ) to a specific, testable inquiry. Broad topics like "global warming" will almost certainly fail. Instead, refine it to something like: "What quantifiable impact did Tokyo's urban greening policy (2010–2020) have on mitigating the urban heat island effect?" Make your question answerable and verifiable.

Essential Principle 2: Choose a topic within one of your DP subjects. Your EE subject should align with a course you are actually taking. Writing an EE in a subject you do not study dramatically increases difficulty.

Essential Principle 3: Ensure you can access necessary data. Avoid topics requiring primary sources or datasets you cannot obtain. Running out of data mid-essay is the most common reason for EE failure.

EE evaluation centres on four dimensions: Research Question quality, Methodology, Analysis, and Reflection.

CAS (Creativity, Activity, Service)—Why You Cannot Ignore It Despite Zero Points

Although CAS carries no numerical score, failing to meet CAS requirements results in Diploma Not Awarded regardless of your subject grades. Over two years, your engagement, reflection, and sustained involvement are assessed.

Practical Strategies:

1. Plan CAS activities before the DP begins. Be ready to start activities in September of Year 1.
2. Connect CAS activities to your DP subjects. If you take Economics HL, volunteering at a microfinance NGO creates a meaningful link between coursework and service, and strengthens your university application Personal Statement.
3. Write reflections immediately after each activity. Do not defer reflections until the end of Year 2. Attempting to write everything at once will compromise quality. Develop the habit of reflecting on each activity right away.

IA (Internal Assessment)—Your "Second Examination" Is as Crucial as the Final Exam

Internal Assessments, submitted in each subject, comprise 20–30% of your final subject grade. Although often overlooked compared to the final examination, weak IA scores force you to score higher on the final exam, creating unnecessary pressure. Conversely, strong IA scores significantly reduce final exam pressure.

IA Format and Weighting by Subject Category

IA embodies the essence of the DP: you choose the topic, conduct the investigation or experiment, and write the report—it represents the DP's commitment to inquiry-based learning.

Essential IA Strategy: Begin topic selection and preliminary research in Year 1. IA submission deadlines typically cluster in Year 2's first half (September–January), overlapping with final EE revisions and TOK essay completion—a period of intense workload. By solidifying your IA direction in Year 1, you significantly reduce Year 2 pressure.

The Two-Year DP Timeline—Planning Backwards from Predicted Grades

The two-year DP follows a clear timeline: IA submissions, EE writing, university applications, and final examinations. Understanding "what to do and when" and planning backwards from this timeline is essential to DP success.

Final subject selection confirmation. CAS activities begin. Start considering EE topic candidates.

Year 1, October–December

First term tests and Mock exams

These form the foundation of your Predicted Score. Approach with full effort.

Year 1, January–March

EE topic finalized, Research Question confirmed

Supervision with your assigned teacher begins

Year 1, April–June

IA preliminary investigation and experiments begin (some subjects)

Plan your summer work schedule for IA and EE writing

Year 1, July–August

Summer holiday

Advance your EE main text significantly during the summer break. This is your critical turning point.

Year 2, September

University application preparation begins

Predicted Score confirmed. Target university list finalized.

Year 2, 15 October

Oxford/Cambridge/Medical UCAS deadline

Apply with Predicted Score and Personal Statement

Year 2, November–January

IA submission deadline. EE final submission

The "crunch period" when IA, EE, and TOK submissions overlap

Year 2, late January

Other UK universities UCAS deadline

Year 2, February–March

TOK essay final submission

Year 2, May

Final exams (global unified)

Six written papers across approximately three weeks

Year 2, July

Results Day

Scores confirmed. Compared against Conditional Offer conditions

The Importance of Predicted Score

Both UK universities and Japanese universities accepting IB entry typically accept applications based on the Predicted Score (the forecast score issued by your school). Because UCAS applications (October–January) take place before the final exams (May), universities issue Conditional Offers based on your Predicted Score, then verify whether your final exam results meet the conditions after May.

This means every grade from your very first term tests in Year 1 is reflected in your Predicted Score. The strategy of "working seriously from Year 2" will not work.

Score Strategy—What to Prioritize to Achieve 40+ Points

The Reality of the DP Through Global Statistics (May 2025 Exams)

Source: IBO Official Statistical Bulletin, May 2025

Only 4.68% of all candidates achieved 40+ points. To pursue Oxford or Cambridge, you need to be in the top 5%.

Securing the 3 Core Points Reliably—The Most Efficient Way to Build Your Score

The 3 core points are determined by a matrix combining TOK and EE grades. If you score A in TOK and A in EE, you earn 3 points; B in TOK and B in EE gives you 1 point.

Scoring 42 points across six subjects (averaging 7 per subject) is extremely difficult, but if you secure the 3 core points reliably, you can reach 42 points with an average of 6.5 across your six subjects (totalling 39 points).

Treating "TOK and EE as throwaway subjects" is the most dangerous strategic mistake. In fact, the 3 core points are a relatively stable area where proper methodology can deliver consistent results.

"Design" Your Score Distribution Across Six Subjects

You do not need to score 7 in every subject. Realistic goal-setting is crucial.

Example score design for targeting 40 points:

HL: 7 + 7 + 6 = 20 points
SL: 6 + 6 + 5 = 17 points
Core: 3 points
Total: 40 points

Achieving a 7 in HL subjects often becomes a condition of the Conditional Offer, so allocate study time strategically to your three HL subjects and focus on "reliably securing 5 or above" in your SL subjects.

The Barriers Non-Native English Speakers Face in the DP and Practical Solutions

Insufficient CALP (Cognitive Academic Language Proficiency) Directly Impacts Your Score

"I speak fluent English in everyday conversation, but my History essay won't move above a B" or "I struggle to write the Evaluation section properly in my Biology IA"—these challenges stem from insufficient CALP (Cognitive Academic Language Proficiency, or academic language ability).

Solution: Master "academic English templates" specific to each subject.

• Presenting analytical findings: "This suggests that..." "The data indicates a correlation between..."
• Acknowledging limitations: "A limitation of this approach is..." "This result should be interpreted with caution because..."
• Testing hypotheses: "The data supports the hypothesis that..." "Contrary to the initial prediction..."

Simply mastering these formulaic expressions by subject can dramatically improve the quality of your essays and IAs.

Overcoming the Fear of TOK and EE's "Open-Ended Questions"

In traditional education, reproduction of correct answers is valued, but the IB evaluates your ability to construct your own argument.

Solution: Start writing small essays from early in Year 1. You cannot write a 4,000-word EE immediately. Begin with 500-word argumentative essays, embed the structure (claim → evidence → counterargument → rebuttal → conclusion) in your practice, then progressively tackle longer papers.

Your Partner Through Two Years of DP—ELT's IB Support

The DP is often compared to climbing Mount Everest—it is demanding, but with the right route and a guide, the summit is achievable. Preventing burnout while strategically building your score is the key to DP success.

At ELT, experienced DP instructors serve as your "Sherpas"—guides accompanying you on your journey.

• Subject instruction: Clear explanations of HL/SL subjects (Math AA/AI, Physics, Chemistry, Economics, and more) delivered in English. We do not hand you answers; we guide you through the thinking process.
• TOK/EE support: One-to-one guidance from topic brainstorming, through logical structure revision, to citation conventions.
• IA feedback: Subject-specific feedback based on IA evaluation rubrics.
• CALP development: Master subject-specific academic English templates to elevate your essay and IA scores.
• Predicted Score strategy: Design a systematic score-building plan from Year 1.
• University applications: Personal Statement revision, target university selection, UCAS support.

View IB support details →