真题逐题分析 — Complete Exam Analysis
Course: COMPSCI 713: AI Fundamentals, University of Auckland Instructor: Xinyu Zhang (mid-semester) / Thomas (final exam, partial) Scope: ALL available exam papers — S1 2025 Sample, S1 2025 Actual, S1 2026 Sample, S1 2024 Final Purpose: Question-by-question breakdown for exam preparation
How to Use This Document(使用指南)
- First pass: Skim the tables at the end of each exam section to see topic/mark distribution
- Second pass: Read the Learning Points for your weakest topics
- Third pass: Use the Common Mistakes as a self-check before the exam
- Final review: Jump to Cross-Exam Patterns at the bottom
💡 核心发现: 每一份试卷都考了 Symbolic Logic, LNN, Knowledge Graphs, 和 Decision Trees/Ensembles。这四个是绝对必考项。
Exam Paper 1: S1 2025 Sample Test
Format: 15 marks, 6 questions, 60 minutes (5 reading + 55 answering) Allowed aids: One double-sided handwritten A4 page
Q1 — Symbolic Logic [3 marks]
Question Summary
(a) Propositional Logic — Modus Tollens [~1.5m]
Scenario: A secure facility grants entry only if a person has a valid ID ($I$) AND fingerprint matches ($F$). Rule: $(I \wedge F) \rightarrow E$. Observed: person was NOT granted entry ($\neg E$).
Task: Deduce what must be true about $I$ and $F$.
(b) First-Order Logic [~1.5m]
Task: Write “Not all birds can fly” in FOL using $\text{Fly}(x)$. Give a realistic example.
Expected Answer
(a):
- By Modus Tollens: $(I \wedge F) \rightarrow E$ and $\neg E$ implies $\neg(I \wedge F)$
- By De Morgan: $\neg I \vee \neg F$
- Conclusion: Either the person lacked a valid ID, or the fingerprint didn’t match (or both)
(b):
- FOL: $\neg \forall x , \text{Fly}(x)$, equivalently $\exists x , \neg \text{Fly}(x)$
- Example: “Penguins are birds but cannot fly”
Analysis
| Item | Detail |
|---|---|
| Topic | Symbolic Logic(符号逻辑) |
| Lecture | W2L1 |
| Type | 推理 + 形式化 (Deduction + Formalisation) |
| Difficulty | ★★☆ |
| Keywords | propositional logic, modus tollens, FOL, universal quantifier, negation |
| Exam intent | Can student apply basic inference rules AND translate English → FOL? |
Learning Points(学习要点)
- Modus Tollens 是本课程考试的第一推理模式: $(P \rightarrow Q), \neg Q \vdash \neg P$。务必熟练到条件反射
- “Not all” = $\neg \forall x$: 注意不是 $\forall x , \neg$(后者意为“所有都不“,语义完全不同)
- De Morgan 定律: $\neg(A \wedge B) = \neg A \vee \neg B$,推导结论时经常用到
⚠️ Common Mistake: Writing $\forall x , \neg \text{Fly}(x)$ which means “NO bird can fly” — much stronger than “not all birds can fly.”
Q2 — Logic Neural Networks (LNN) [2 marks]
Question Summary
Scenario: Smart home LNN rule: HeatingOn $\leftarrow$ Cold $\otimes$ AtHome (differentiable AND).
(a) Interpret in natural language. How does it differ from Boolean? [1m]
(b) Compute with Cold = 0.9, AtHome = 0.4. Discuss whether heating activates. [1m]
Expected Answer
(a):
- Natural language: “If it is cold AND someone is at home, turn on the heating.”
- Difference: Boolean AND requires both inputs strictly TRUE (1). LNN’s $\otimes$ works with continuous truth values in $[0, 1]$, producing intermediate results that capture partial truth and enable gradient-based learning.
(b):
- Product t-norm: $0.9 \times 0.4 = 0.36$
- Lukasiewicz: $\max(0, 0.9 + 0.4 - 1) = 0.3$
- Whether heating activates depends on threshold: if $\alpha = 0.3$, yes; if $\alpha = 0.7$, no.
Analysis
| Item | Detail |
|---|---|
| Topic | Logic Neural Networks(逻辑神经网络) |
| Lecture | W2L2 |
| Type | 概念解释 + 计算 (Explain + Compute) |
| Difficulty | ★★☆ |
| Keywords | LNN, soft conjunction, t-norm, product, Lukasiewicz, threshold |
| Exam intent | Why do we need differentiable logic? Can student compute with t-norms? |
Learning Points
- 必背三个 t-norm:
- Product: $a \times b$
- Lukasiewicz: $\max(0, a + b - 1)$
- Godel/min: $\min(a, b)$
- Boolean vs LNN 的关键差异: Boolean 是离散的 {0,1};LNN 是连续的 [0,1],支持梯度下降
⚠️ Common Mistake: Forgetting to discuss the threshold. Computing 0.36 is not enough — you must state what activation decision follows.
Q3 — Knowledge Graph Embeddings [2 marks]
Question Summary
Explain the role of entity/relation embeddings in KG completion. Introduce a common KG inference task with an example.
Expected Answer
- Embeddings: Map entities and relations to dense vectors in continuous space, enabling mathematical operations for reasoning
- Inference task: Link prediction — given $(h, r, ?)$, predict tail entity
- Example: $(Einstein, bornIn, ?) \rightarrow Germany$
Analysis
| Item | Detail |
|---|---|
| Topic | Knowledge Graphs(知识图谱) |
| Lecture | W3L2 |
| Type | 概念解释 + 举例 (Explain + Example) |
| Difficulty | ★☆☆ |
| Keywords | KG embedding, TransE, link prediction, knowledge completion |
Learning Points
- TransE 核心公式: $h + r \approx t$(头实体向量 + 关系向量 ≈ 尾实体向量)
- 三种推理任务: tail prediction $(h, r, ?)$, head prediction $(?, r, t)$, relation prediction $(h, ?, t)$
⚠️ Common Mistake: Confusing “embedding” with “one-hot encoding.” Embeddings are dense, low-dimensional, learned vectors — not sparse indicator vectors.
Exam tip(答题技巧): 永远给具体例子。“(Einstein, bornIn, ?) → Germany” 远比 “it predicts missing links” 好。
Q4 — Embodied AI / Robot Soccer [2 marks]
Question Summary
Robot soccer league: overhead camera, 225 features per frame, team of 5 robots, no inter-robot communication. Describe strategies/collective behaviours.
Expected Answer
Any of (1 mark each, max 2):
- Collective behaviours: passing strategy, interception prediction, passing point value assessment
- Positioning strategies: formations for attack/defense
- Role-based strategies: dynamic role assignment based on game situation
- Centralized control: overhead camera acts as single controller for all 5 robots
Analysis
| Item | Detail |
|---|---|
| Topic | Embodied AI / Multi-Agent Systems(具身AI/多智能体) |
| Lecture | Multi-Agent lecture |
| Type | 知识回忆 (Recall) |
| Difficulty | ★☆☆ |
| Exam intent | Tests lecture attendance — can you name concrete strategies? |
Learning Points
- 三大策略类别: (1) 集体行为 — passing, (2) 位置策略 — formation, (3) 角色分配 — dynamic assignment
- 关键细节: No communication → centralized control via overhead camera → single decision-maker
⚠️ Common Mistake: Being too vague. “They work together” = 0 marks. Name specific strategies.
Q5 — Random Forest / Bagging [3 marks]
Question Summary
Dataset with 225 features.
(a) How are features selected per tree? How many? [2m]
(b) Why is feature bagging a good idea? [1m]
Expected Answer
(a):
- Random subset of features sampled per tree (not all 225)
- Typical: $\sqrt{p} = \sqrt{225} = 15$ features per tree
- Different trees see different feature subsets
(b):
- Prevents trees from being highly correlated (e.g., same dominant feature always at root)
- Decorrelated trees → ensemble averaging reduces variance more effectively
Analysis
| Item | Detail |
|---|---|
| Topic | Decision Trees & Ensembles(决策树与集成方法) |
| Lecture | W4L2 |
| Type | 解释 + 计算 (Explain + Calculate) |
| Difficulty | ★★☆ |
| Exam intent | Tests “why” not just “what” — understanding the purpose of feature bagging |
Learning Points
- $\sqrt{p}$ rule: For $p$ features, sample $\sqrt{p}$ per tree. For 225 features → 15.
- Bagging vs Boosting:
- Bagging → parallel trees → reduces variance
- Boosting → sequential trees → reduces bias
- 两层随机化: (1) Bootstrap sampling of data rows, (2) Random sampling of features. Both reduce correlation.
⚠️ Common Mistake: Confusing bootstrap sampling (random data points) with feature bagging (random features). Both happen in Random Forest; they serve different purposes.
Q6 — MYCIN / Expert Systems [3 marks]
Question Summary
Medical diagnosis scenario using backward chaining. Patient has a runny nose. Possible diagnoses: common cold, allergies, measles. Demonstrate backward chaining reasoning.
Expected Answer
- Backward chaining: Start from hypothesis, work backward to check conditions
- Hypothesis: Common Cold → needs runny nose ✓, fever ?, cough ?
- Hypothesis: Allergies → needs runny nose ✓, sneezing ?, itchy eyes ?
- Hypothesis: Measles → needs runny nose ✓, rash ?, high fever ?
- Ask additional questions to discriminate between hypotheses
- Contrast with forward chaining: start from facts, derive conclusions
Analysis
| Item | Detail |
|---|---|
| Topic | Expert Systems / MYCIN(专家系统) |
| Lecture | W3L1 (Knowledge Representation) |
| Type | 推理过程演示 (Demonstrate reasoning process) |
| Difficulty | ★★☆ |
| Keywords | backward chaining, hypothesis, rule-based reasoning, MYCIN |
| Exam intent | Can student trace backward chaining step by step? |
Learning Points
- Backward chaining 三步法: (1) Start with hypothesis, (2) Check conditions, (3) Ask for missing info
- Forward vs Backward: Forward = data-driven (fact → conclusion); Backward = goal-driven (hypothesis → verify)
- MYCIN 特色: Uses certainty factors (CF) instead of probabilities; backward chaining for diagnosis
⚠️ Common Mistake: Describing forward chaining when asked for backward chaining. Direction matters!
S1 2025 Sample Test — Summary Table
| Q | Topic | Marks | % | Cognitive Level |
|---|---|---|---|---|
| Q1 | Symbolic Logic | 3 | 20% | Apply + Formalise |
| Q2 | LNN | 2 | 13% | Explain + Compute |
| Q3 | KG Embeddings | 2 | 13% | Explain + Exemplify |
| Q4 | Robot Soccer | 2 | 13% | Recall |
| Q5 | Random Forest | 3 | 20% | Explain + Calculate |
| Q6 | MYCIN / Expert Systems | 3 | 20% | Demonstrate reasoning |
| Total | 15 | 100% |
Exam Paper 2: S1 2025 Actual Test
Format: 15 marks, 6 questions, 60 minutes This is the REAL exam that was sat
Q1 — Symbolic Logic [2 marks]
Question Summary
(a) Given $(P \vee Q) \rightarrow R$ and $\neg R$. Apply Modus Tollens. [1m]
(b) Given $\forall x(\text{Cheat}(x) \rightarrow \text{Disqualified}(x))$ and Alice is not disqualified. Conclude about Alice. [1m]
Expected Answer
(a):
- Modus Tollens: $(P \vee Q) \rightarrow R$ and $\neg R$ implies $\neg(P \vee Q)$
- By De Morgan: $\neg P \wedge \neg Q$
- Both P and Q must be false
(b):
- Universal instantiation: $\text{Cheat}(\text{Alice}) \rightarrow \text{Disqualified}(\text{Alice})$
- Given $\neg \text{Disqualified}(\text{Alice})$, by Modus Tollens: $\neg \text{Cheat}(\text{Alice})$
- Conclusion: Alice did not cheat
Analysis
| Item | Detail |
|---|---|
| Topic | Symbolic Logic(符号逻辑) |
| Lecture | W2L1 |
| Type | 推理 (Pure deduction) |
| Difficulty | ★★☆ |
| Keywords | modus tollens, disjunction, De Morgan, universal instantiation, FOL |
| Exam intent | Modus Tollens again! Plus combining FOL with propositional reasoning |
Learning Points
- 这道题和 Sample 的区别: Sample 用 $(I \wedge F) \rightarrow E$,Actual 用 $(P \vee Q) \rightarrow R$。结论不同!
- $\neg(A \wedge B) = \neg A \vee \neg B$(至少一个为假)
- $\neg(A \vee B) = \neg A \wedge \neg B$(两个都假)
- FOL + Modus Tollens 组合拳: Universal instantiation 先把 $\forall x$ 具体化为 Alice,再用 Modus Tollens
⚠️ Common Mistake: For $\neg(P \vee Q)$, some students write “$P$ or $Q$ is false” — this is WRONG. BOTH must be false. De Morgan on disjunction gives conjunction of negations.
🔑 关键对比: AND 的否定 → 至少一个假 (disjunction); OR 的否定 → 全部假 (conjunction). 这是必须刻在脑子里的。
Q2 — LNN with Truth Bounds [3 marks]
Question Summary
Scenario: Autonomous vehicle collision alert system. Two sensors:
- Pedestrian detector: $P$ with bounds $[L_P, U_P] = [0.8, 0.9]$
- Obstacle detector: $Q$ with bounds $[L_Q, U_Q] = [0.3, 0.6]$
Rule: Alert $\leftarrow P \vee Q$ (disjunction, not conjunction!)
Alert threshold: $\alpha = 0.7$
(a) Determine alert status [2m]
(b) Why are bounds (instead of point estimates) useful in safety-critical applications? [1m]
Expected Answer
(a):
-
Co-norm for OR (using Lukasiewicz):
- Lower bound: $\min(1, L_P + L_Q) = \min(1, 0.8 + 0.3) = 1.0$
- Upper bound: $\min(1, U_P + U_Q) = \min(1, 0.9 + 0.6) = 1.0$
-
OR result bounds: $[1.0, 1.0]$
-
Since lower bound $1.0 \geq \alpha = 0.7$: Alert ACTIVATES
Alternative (product-based co-norm):
- $P \vee Q = P + Q - P \cdot Q$
- Lower: $0.8 + 0.3 - 0.8 \times 0.3 = 0.86$
- Upper: $0.9 + 0.6 - 0.9 \times 0.6 = 0.96$
- Bounds: $[0.86, 0.96]$, both $\geq 0.7$: Alert ACTIVATES
(b):
- Bounds capture epistemic uncertainty — we know the truth value lies somewhere in the interval
- In safety-critical systems, we can make conservative decisions: if even the lower bound exceeds threshold, we act
- Point estimates hide uncertainty; bounds let us reason about worst-case scenarios
Analysis
| Item | Detail |
|---|---|
| Topic | LNN with Truth Bounds(带真值边界的 LNN) |
| Lecture | W2L2 |
| Type | 计算 + 论述 (Compute + Argue) |
| Difficulty | ★★★ |
| Keywords | LNN, truth bounds, co-norm, disjunction, safety-critical, epistemic uncertainty |
| Exam intent | Can student compute with bounds (not just point values)? Understands safety implications? |
Learning Points
- 这是 LNN 的升级版考法: Sample 考 AND 的点值计算,Actual 考 OR 的区间计算
- AND vs OR t-norm/co-norm:
- AND (t-norm): Product → $a \times b$; Lukasiewicz → $\max(0, a + b - 1)$
- OR (co-norm): Product → $a + b - a \times b$; Lukasiewicz → $\min(1, a + b)$
- Safety-critical reasoning: 用 lower bound 做决策 = 最保守策略
⚠️ Common Mistake: Using AND formula when the question says OR! Read the operator carefully: $\otimes$ = AND, $\oplus$ = OR, $\vee$ = OR.
⚠️ 另一个常见错误: 忘记 bounds 是区间运算。不能只算一个值,要算 [lower, upper]。
Q3 — Knowledge Graphs / TransE [2 marks]
Question Summary
(a) Explain the TransE embedding model [1m]
(b) Write the TransE scoring function [1m]
Expected Answer
(a):
- TransE represents entities and relations as vectors in the same space
- Core idea: for a true triple $(h, r, t)$, the head plus relation should approximate the tail: $h + r \approx t$
(b):
- Scoring function: $f(h, r, t) = |h + r - t|$ (L1 or L2 norm)
- Lower score = more likely to be true
- Training: minimize score for true triples, maximize for false (negative sampling)
Analysis
| Item | Detail |
|---|---|
| Topic | Knowledge Graphs / TransE |
| Lecture | W3L2 |
| Type | 概念 + 公式 (Concept + Formula) |
| Difficulty | ★☆☆ |
| Exam intent | TransE is the simplest and most testable KG model — can you state the formula? |
Learning Points
- TransE 必背: $f(h,r,t) = |h + r - t|$,越小越可能是真三元组
- 与 Sample 的区别: Sample 考概念层面(什么是 embedding),Actual 考公式层面(TransE 具体怎么算)
- 局限性: TransE 无法建模 1-to-N 关系(如一个国家有多个城市)
⚠️ Common Mistake: Writing $h + r = t$ (equality) instead of $h + r \approx t$ (approximation). The model learns to minimize the distance, not enforce exact equality.
Q4 — Decision Trees / CART [2 marks]
Question Summary
What does “greedy” mean in the context of CART (Classification and Regression Trees)?
Expected Answer
- Greedy = at each node, CART picks the locally optimal split (maximum information gain or minimum Gini impurity) without considering future splits
- It does not evaluate all possible tree structures to find the global optimum
- This makes it computationally efficient but potentially suboptimal
- Why greedy? Finding the optimal tree is NP-hard
Analysis
| Item | Detail |
|---|---|
| Topic | Decision Trees(决策树) |
| Lecture | W4L1-L2 |
| Type | 概念解释 (Concept explanation) |
| Difficulty | ★☆☆ |
| Keywords | CART, greedy algorithm, local optimum, information gain, Gini impurity |
| Exam intent | Tests understanding of algorithm design philosophy, not just mechanics |
Learning Points
- “Greedy“三要素: (1) 每步选当前最优 (2) 不回溯 (3) 不保证全局最优
- 为什么接受 greedy?: 找最优树是 NP-hard;greedy 在实践中效果够好
- Ensemble 弥补 greedy: Random Forest 通过多棵 greedy tree 的聚合来逼近更好的解
⚠️ Common Mistake: Saying greedy means “fast.” Greedy is about the optimization strategy (local vs global), not speed.
Q5 — Fuzzy Logic [3 marks]
Question Summary
Contrast traditional (Boolean) logic vs fuzzy logic for the rule: IF athlete is STRONG AND athlete is HEAVY THEN athlete is HAMMER_THROWER
Expected Answer
Traditional Logic:
- STRONG = {yes, no}, HEAVY = {yes, no} → HAMMER_THROWER = {yes, no}
- Sharp boundaries: an athlete is either strong or not
- AND = Boolean AND: both must be true for conclusion to hold
Fuzzy Logic:
- STRONG(x) ∈ [0, 1], HEAVY(x) ∈ [0, 1] → HAMMER_THROWER(x) ∈ [0, 1]
- Gradual membership: “somewhat strong” = 0.6, “very heavy” = 0.9
- AND = t-norm (e.g., min): HAMMER_THROWER ≥ min(0.6, 0.9) = 0.6
- Captures vagueness — no sharp cutoff between “strong” and “not strong”
Analysis
| Item | Detail |
|---|---|
| Topic | Fuzzy Logic / Soft Computing |
| Lecture | W5L1 |
| Type | 对比分析 (Compare & Contrast) |
| Difficulty | ★★☆ |
| Exam intent | Core theme: why do we need fuzzy logic? What problem does it solve? |
Learning Points
- 对比答题模板: 分三行写 — (1) Traditional: binary, (2) Fuzzy: continuous, (3) WHY fuzzy is better for this case
- Fuzzy logic 解决 vagueness: “Strong” 没有明确边界 → 需要 membership function
- 给具体数字: 说 “STRONG(athlete) = 0.6” 比抽象描述好得多
⚠️ Common Mistake: Confusing fuzzy logic with probability. Fuzzy = degree of membership (to what extent is this athlete “strong”?). Probability = likelihood of an event (what’s the chance this athlete wins?).
Q6 — GA / Embodied AI [3 marks]
Question Summary
Design a fitness function for a BigDog walking robot using Genetic Algorithm optimization.
Expected Answer
Fitness function components:
- Distance traveled (primary): $f_1 = d / d_{max}$ — further is better
- Stability (constraint): $f_2 = 1 - \text{angular_deviation} / \text{max_deviation}$ — less wobble is better
- Energy efficiency (secondary): $f_3 = 1 - E_{used} / E_{max}$ — less energy is better
- Penalty: $f_{penalty} = -C$ if robot falls
Combined: $F = w_1 f_1 + w_2 f_2 + w_3 f_3 + f_{penalty}$
Key design considerations:
- Must balance multiple objectives
- Weights reflect priority (distance > stability > efficiency typically)
- Penalties for catastrophic failure (falling) should be large
Analysis
| Item | Detail |
|---|---|
| Topic | Genetic Algorithms / Fitness Function Design(遗传算法/适应度函数设计) |
| Lecture | GA/NEAT lectures |
| Type | 设计题 (Design) |
| Difficulty | ★★★ |
| Keywords | fitness function, multi-objective, GA, embodied AI, BigDog |
| Exam intent | Can student translate a real-world goal into a mathematical optimization objective? |
Learning Points
- Fitness function 设计万能框架: (1) 定义主目标, (2) 加约束, (3) 加惩罚项, (4) 用加权求和合并
- 开放题没有唯一答案: 关键是逻辑自洽 + 覆盖关键方面
- 必须提到权衡: 速度 vs 稳定性 vs 能耗
⚠️ Common Mistake: Only considering one objective (e.g., just distance). Real fitness functions must balance multiple competing goals.
S1 2025 Actual Test — Summary Table
| Q | Topic | Marks | % | Cognitive Level |
|---|---|---|---|---|
| Q1 | Symbolic Logic (Modus Tollens + FOL) | 2 | 13% | Apply + Deduce |
| Q2 | LNN (Truth Bounds + OR) | 3 | 20% | Compute + Argue |
| Q3 | KG / TransE | 2 | 13% | Explain + Formula |
| Q4 | Decision Trees (CART greedy) | 2 | 13% | Explain concept |
| Q5 | Fuzzy Logic | 3 | 20% | Compare & Contrast |
| Q6 | GA / Fitness Function Design | 3 | 20% | Design |
| Total | 15 | 100% |
Exam Paper 3: S1 2026 Sample Test
Format: 20 marks, 6 questions, 60 minutes (5 reading + 55 answering) Note: Marks increased from 15 → 20. Same topics, more depth required.
Q1 — Symbolic Logic [5 marks]
Question Summary
(a) Propositional Logic — with Truth Table [3m]
Same scenario as S1 2025 Sample: $(I \wedge F) \rightarrow E$, given $\neg E$. But now explicitly requires a truth table for full marks.
(b) FOL — Birds [2m]
Same “not all birds can fly” question.
Expected Answer
(a):
Step 1: Truth table for $X \rightarrow E$ where $X = I \wedge F$:
| $X$ | $E$ | $X \rightarrow E$ |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 1 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
When $E = 0$ and implication is TRUE: $X$ must be 0. [1 mark]
Step 2: Truth table for $I \wedge F$:
| $I$ | $F$ | $I \wedge F$ |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
$I \wedge F = 0$ when at least one is 0. [1 mark]
Step 3: Conclusion — person either lacked valid ID, or fingerprint didn’t match, or both. [1 mark]
(b):
- $\neg \forall x , \text{Fly}(x)$ [1 mark]
- Example: penguins, ostriches, kiwi (kiwi 特别适合 UoA 的语境!) [1 mark]
Analysis
| Item | Detail |
|---|---|
| Topic | Symbolic Logic |
| Lecture | W2L1 |
| Difficulty | ★★☆ |
| Compared to 2025 | Same scenario, more marks → must show truth table explicitly |
Learning Points
- 2026 版本更重视过程: 3 marks for truth table vs 2025’s ~1.5 marks. Show ALL steps.
- 真值表是得分保障: 即使你能直接用 Modus Tollens 推出结论,画真值表拿更稳的分
💡 策略提示: 5 marks = 25% of total. Spend proportional time (~14 minutes). Don’t rush the truth table.
Q2 — LNN [4 marks]
Question Summary
Same HeatingOn scenario as S1 2025 Sample, but 4 marks (was 2).
(a) Interpret rule + compare with Boolean [2m]
(b) Compute with Cold = 0.9, AtHome = 0.4 [2m]
Expected Answer
Same as S1 2025 Sample Q2 but more detail expected for the extra marks:
- (a): Need deeper comparison — mention gradient-based learning, continuous optimization, partial truth
- (b): Show at least two t-norms, discuss threshold selection, explain practical implications
Analysis
| Item | Detail |
|---|---|
| Topic | LNN |
| Compared to 2025 | Same question, doubled marks → expects more thorough answer |
| Difficulty | ★★☆ |
Learning Points
- More marks = more depth expected:
- 2m version: basic computation + brief threshold mention
- 4m version: multiple t-norms + threshold discussion + why LNN matters for AI
- 安全策略: 写出所有你知道的 t-norm 计算结果,对比它们
Q3 — Knowledge Graph Embeddings [2 marks]
Question Summary
Same as S1 2025 Sample Q3: explain entity/relation embeddings + KG inference task + example.
Expected Answer
Identical to S1 2025 Sample Q3. (See above.)
Learning Points
- 三年不变: 这道题完全一样。说明 KG embedding 是必考的固定题型。
Q4 — Robot Soccer [2 marks]
Question Summary
Same as S1 2025 Sample Q4: overhead camera, 225 features, describe strategies.
Expected Answer
Identical to S1 2025 Sample Q4. (See above.)
Learning Points
- 同样三年不变: Robot Soccer 策略也是固定考点。
Q5 — Random Forest [3 marks]
Question Summary
Same as S1 2025 Sample Q5: feature selection + why feature bagging.
Expected Answer
Identical to S1 2025 Sample Q5. (See above.)
Q6 — Vagueness vs Uncertainty [4 marks]
Question Summary
New question type (not in S1 2025 Sample):
Classify 4 scenarios:
- Patient described as “high risk” → Vagueness
- Security system estimates burglary → Uncertainty
- Student rated “almost excellent” → Vagueness
- Spam filter classifies email → Uncertainty
Expected Answer
| Scenario | Classification | Reasoning |
|---|---|---|
| “high risk” patient | Vagueness | Blurry boundary — what counts as “high”? Degree, not yes/no |
| Alarm/burglary estimate | Uncertainty | Unknown ground truth — did burglary actually happen? |
| “almost excellent” student | Vagueness | Gradual concept — no sharp boundary between “good” and “excellent” |
| Spam filter | Uncertainty | Probabilistic inference — inferring unknown class from features |
Analysis
| Item | Detail |
|---|---|
| Topic | Soft Computing — Vagueness vs Uncertainty |
| Lecture | W5L1 |
| Difficulty | ★☆☆ (if you know the distinction) |
| Exam intent | THE central philosophical distinction of soft computing |
Learning Points
- 万能判断法则:
- Vagueness → “To what degree?” → Fuzzy Logic (membership functions)
- Uncertainty → “How likely?” → Bayesian Reasoning (probabilities)
- 快速测试: 概念边界模糊 → vagueness; 世界状态未知 → uncertainty
- 语言线索: “high”, “almost”, “kind of” → vagueness; “estimate”, “predict”, “classify” → uncertainty
⚠️ Common Mistake: Thinking fuzzy logic handles uncertainty. NO — fuzzy handles vagueness; Bayes handles uncertainty. This is THE most important distinction in W5.
S1 2026 Sample Test — Summary Table
| Q | Topic | Marks | % | Cognitive Level |
|---|---|---|---|---|
| Q1 | Symbolic Logic (truth table + FOL) | 5 | 25% | Apply + Formalise |
| Q2 | LNN (soft AND computation) | 4 | 20% | Explain + Compute |
| Q3 | KG Embeddings | 2 | 10% | Explain + Exemplify |
| Q4 | Robot Soccer | 2 | 10% | Recall |
| Q5 | Random Forest / Bagging | 3 | 15% | Explain + Calculate |
| Q6 | Vagueness vs Uncertainty | 4 | 20% | Classify scenarios |
| Total | 20 | 100% |
Exam Paper 4: S1 2024 Final Exam (Thomas’s Section)
Note: This is the final exam (not mid-semester), with questions from a different instructor (Thomas). These topics may or may not appear in 2026’s mid-semester, but they are useful for final exam preparation and general knowledge.
Q1 — Continual Learning [4 marks]
Question Summary
Concept drift, replay methods, Gaussian Mixture Models in continual learning.
Expected Answer
- Concept drift: Data distribution changes over time; model must adapt
- Replay methods: Store subset of old data; replay during training on new data to prevent catastrophic forgetting
- GMM: Can be used to model data distributions; detect drift by comparing distributions
- Stability-plasticity tradeoff: Too much stability → can’t learn new; too much plasticity → forgets old
Analysis
| Item | Detail |
|---|---|
| Topic | Continual Learning(持续学习) |
| Difficulty | ★★☆ |
| Priority for 2026 mid-sem | 🟢 LOW — Thomas’s topic, unlikely in mid-semester |
Q2 — BFS vs UCS [3 marks]
Question Summary
Compare Breadth-First Search and Uniform-Cost Search.
Expected Answer
- BFS: Expands shallowest node first; optimal when all edge costs equal; uses FIFO queue
- UCS: Expands lowest-cost node first; optimal for any non-negative costs; uses priority queue
- Key difference: BFS = optimal for unweighted; UCS = optimal for weighted graphs
Analysis
| Item | Detail |
|---|---|
| Topic | Search Algorithms |
| Priority for 2026 mid-sem | 🟢 LOW — not in Xinyu’s question pattern |
Q3 — MCTS / UCB1 [3 marks]
Question Summary
Explain the components of the UCB1 formula used in Monte Carlo Tree Search.
Expected Answer
$$UCB1 = \bar{X}_j + C \sqrt{\frac{\ln N}{n_j}}$$
- $\bar{X}_j$: average reward of node $j$ (exploitation term)
- $N$: total visits to parent
- $n_j$: visits to node $j$
- $C$: exploration constant
- $\sqrt{\ln N / n_j}$: exploration term — favors less-visited nodes
- Balances exploration vs exploitation
Analysis
| Item | Detail |
|---|---|
| Topic | MCTS / UCB1 |
| Priority for 2026 mid-sem | 🟡 MEDIUM — exploration-exploitation could appear in GA context |
Q4 — RL for Pac-Man [1 mark]
Question Summary
Define state, action, policy, reward for RL applied to Pac-Man.
Expected Answer
- State: Current game board configuration (ghost positions, pellet locations, Pac-Man position)
- Action: Move direction (up, down, left, right)
- Policy: Mapping from state to action (which direction to move in each situation)
- Reward: +10 eating pellet, +200 eating ghost, -500 dying, -1 per time step
Analysis
| Item | Detail |
|---|---|
| Topic | Reinforcement Learning(强化学习) |
| Priority for 2026 mid-sem | 🟢 LOW |
Q5 — GNN [2 marks]
Question Summary
Explain permutation invariance and permutation equivariance in Graph Neural Networks.
Expected Answer
- Permutation invariance: Output doesn’t change when node ordering changes (graph-level prediction)
- Permutation equivariance: Output permutes consistently with input permutation (node-level embeddings)
Analysis
| Item | Detail |
|---|---|
| Topic | Graph Neural Networks |
| Priority for 2026 mid-sem | 🟢 LOW — not in Xinyu’s observed pattern |
Q6 — Self-Supervised Learning [2 marks]
Question Summary
Distinguish pretext tasks from downstream tasks in self-supervised learning.
Expected Answer
- Pretext task: Artificial task designed to learn representations without labels (e.g., predict rotation, fill masked words)
- Downstream task: Actual target task the representations are used for (e.g., classification, NER)
- Relationship: Pretext → learn general features; fine-tune on downstream task with few labels
Analysis
| Item | Detail |
|---|---|
| Topic | Self-Supervised Learning |
| Priority for 2026 mid-sem | 🟢 LOW |
Additional Topics from S1 2024 Final (Answer Key)
The following topics appeared in the S1 2024 final exam answer key:
| Topic | Content | Priority for Mid-Sem |
|---|---|---|
| DQN | Online vs target network, bootstrapping | 🟢 LOW |
| Self-Attention | Q/K/V vectors, advantage over traditional attention | 🟡 MEDIUM |
| LLM System Design | Technical route for LLM-based system | 🟡 MEDIUM |
| Decision Tree vs Forest | Interpretability/efficiency trade-off | 🟠 HIGH (DT is core) |
| Naive Bayes | Conditional independence, feature relevance assumptions | 🟡 MEDIUM |
| NEAT | Mobile robot application, fitness function design | 🟠 HIGH (GA/NEAT is core) |
| Self-Supervised Learning | Pretext/downstream tasks | 🟢 LOW |
| Replay in Continual Learning | Stability-plasticity tradeoff | 🟢 LOW |
| CNN in Self-Driving | CNN application in autonomous vehicles | 🟡 MEDIUM |
Cross-Exam Patterns(跨卷规律总结)
Pattern 1: Repeated Questions(原题重复出现)
以下题目在多份试卷中几乎一模一样地出现:
| Question | S1 2025 Sample | S1 2025 Actual | S1 2026 Sample |
|---|---|---|---|
| $(I \wedge F) \rightarrow E$, $\neg E$ → Modus Tollens | ✅ | variant: $(P \vee Q) \rightarrow R$ | ✅ (with truth table) |
| FOL: “Not all birds can fly” | ✅ | variant: Cheat/Disqualified | ✅ |
| LNN HeatingOn ← Cold ⊗ AtHome | ✅ | variant: Bounds + OR | ✅ |
| KG embeddings + inference task | ✅ | variant: TransE formula | ✅ |
| Robot Soccer strategies | ✅ | — | ✅ |
| Random Forest feature bagging | ✅ | variant: CART greedy | ✅ |
| MYCIN backward chaining | ✅ | — | — |
| Fuzzy logic contrast | — | ✅ | — |
| Vagueness vs Uncertainty | — | — | ✅ |
| GA fitness function | — | ✅ | — |
💡 核心发现: Xinyu 喜欢在 Sample Test 和 Actual Test 之间做微调而非大改。Sample 就是 Actual 的预告片!
Pattern 2: Question Evolution(题目进化路径)
每个核心考点在不同年份有“升级版“:
Symbolic Logic 进化链:
S1 2025 Sample: (I∧F)→E, ¬E → 推理(无真值表要求)
S1 2025 Actual: (P∨Q)→R, ¬R → 推理 + FOL 组合
S1 2026 Sample: 同 2025 Sample 但要求画真值表,5 marks
→ 趋势: 从 “能推理” → “能推理 + 证明过程” → “能推理 + 证明 + 变体”
LNN 进化链:
S1 2025 Sample: 点值计算 (AND), 2 marks
S1 2025 Actual: 区间计算 (OR) + safety reasoning, 3 marks
S1 2026 Sample: 点值计算 (AND), 4 marks (deeper explanation)
→ 趋势: AND 和 OR 交替考,区间 vs 点值交替考
KG 进化链:
S1 2025 Sample: "Explain embeddings" (概念)
S1 2025 Actual: "Write TransE formula" (公式)
S1 2026 Sample: "Explain embeddings" (概念, 同2025 Sample)
→ 趋势: 概念和公式交替考。两手都要准备。
Pattern 3: Mark Allocation Trends
| Topic | 2025 Sample (15m) | 2025 Actual (15m) | 2026 Sample (20m) |
|---|---|---|---|
| Symbolic Logic | 3m (20%) | 2m (13%) | 5m (25%) |
| LNN | 2m (13%) | 3m (20%) | 4m (20%) |
| KG | 2m (13%) | 2m (13%) | 2m (10%) |
| Decision Trees/RF | 3m (20%) | 2m (13%) | 3m (15%) |
| Soft Computing/Fuzzy | — | 3m (20%) | 4m (20%) |
| Embodied AI/GA | 2m (13%) | 3m (20%) | 2m (10%) |
| Expert Systems | 3m (20%) | — | — |
Key insight: Symbolic Logic + LNN consistently take 35-45% of total marks. These two topics alone are worth nearly half the exam.
Pattern 4: Cognitive Level Distribution
| Level | Description | Typical % |
|---|---|---|
| Recall | Name strategies, list features | ~15% |
| Explain | Describe how/why something works | ~30% |
| Compute | Calculate t-norm, truth table, $\sqrt{p}$ | ~25% |
| Compare | Fuzzy vs Boolean, vagueness vs uncertainty | ~15% |
| Design | Fitness function, system strategy | ~15% |
Topic Priority Matrix for 2026 Mid-Semester(2026 期中复习优先级)
Based on cross-exam analysis, here is the definitive priority ranking:
| Priority | Topic | Expected Marks | Study Time |
|---|---|---|---|
| 🔴 MUST | Symbolic Logic (Modus Tollens + truth table + FOL) | 4-5m | 20% |
| 🔴 MUST | LNN (AND/OR, point/bounds, t-norm/co-norm) | 3-4m | 20% |
| 🔴 MUST | Knowledge Graphs (TransE, embeddings, inference) | 2m | 10% |
| 🔴 MUST | Decision Trees & Random Forest (greedy, bagging, $\sqrt{p}$) | 2-3m | 10% |
| 🔴 MUST | Soft Computing (vagueness vs uncertainty, fuzzy vs Boolean) | 3-4m | 15% |
| 🟠 HIGH | Embodied AI / Robot Soccer (strategies, centralized control) | 2m | 8% |
| 🟠 HIGH | GA / NEAT (fitness function design) | 2-3m | 10% |
| 🟠 HIGH | Expert Systems / MYCIN (backward chaining) | 0-3m | 5% |
| 🟡 MEDIUM | Naive Bayes (conditional independence) | 0-2m | 2% |
Exam Strategy Recommendations(应试策略建议)
Time Management(时间分配)
For a 20-mark, 55-minute exam:
- ~2.75 minutes per mark
- Q1 (5m): ~14 minutes
- Q2 (4m): ~11 minutes
- Q3 (2m): ~5.5 minutes
- Q4 (2m): ~5.5 minutes
- Q5 (3m): ~8 minutes
- Q6 (4m): ~11 minutes
Cheatsheet Priorities(A4 速查表优先写什么)
Your double-sided A4 page should include (in order of priority):
- Truth table templates — implication, AND, OR truth tables pre-drawn
- Modus Tollens + De Morgan — write the formulas
- T-norm / Co-norm formulas — all 3 variants for AND and OR
- LNN bounds computation — interval arithmetic rules
- TransE formula — $f(h,r,t) = |h + r - t|$
- $\sqrt{p}$ formula — for Random Forest feature bagging
- Vagueness vs Uncertainty — decision table with examples
- Backward vs Forward chaining — one-line definitions
- Fitness function template — multi-objective weighted sum
- Key FOL patterns — $\neg \forall x = \exists x \neg$
Answer Writing Tips(答题技巧)
- Show your work: 2026 version gives more marks for process (truth tables, step-by-step computation)
- Give concrete examples: “(Einstein, bornIn, ?) → Germany” > “it predicts missing links”
- Use the scenario: Refer back to the specific context (smart home, autonomous vehicle, etc.)
- Label your steps: “Step 1: … Step 2: … Therefore: …”
- Quality over quantity: The exam explicitly states this. Be concise and precise.
- When asked “why”: Give the mechanism, not just the outcome. “Feature bagging decorrelates trees, making ensemble averaging more effective at reducing variance.”
Appendix: Complete Question Index(完整题目索引)
For quick reference, every question across all papers:
| Paper | Q# | Marks | Topic | Key Task |
|---|---|---|---|---|
| 2025 Sample | Q1 | 3 | Symbolic Logic | Modus Tollens + FOL |
| 2025 Sample | Q2 | 2 | LNN | AND computation |
| 2025 Sample | Q3 | 2 | KG | Embeddings + inference |
| 2025 Sample | Q4 | 2 | Robot Soccer | List strategies |
| 2025 Sample | Q5 | 3 | Random Forest | Feature bagging |
| 2025 Sample | Q6 | 3 | MYCIN | Backward chaining |
| 2025 Actual | Q1 | 2 | Symbolic Logic | Modus Tollens (OR variant) + FOL |
| 2025 Actual | Q2 | 3 | LNN | Bounds + OR + safety |
| 2025 Actual | Q3 | 2 | KG / TransE | TransE formula |
| 2025 Actual | Q4 | 2 | Decision Trees | CART greedy |
| 2025 Actual | Q5 | 3 | Fuzzy Logic | Boolean vs Fuzzy |
| 2025 Actual | Q6 | 3 | GA / BigDog | Fitness function design |
| 2026 Sample | Q1 | 5 | Symbolic Logic | Truth table + FOL |
| 2026 Sample | Q2 | 4 | LNN | AND computation (deeper) |
| 2026 Sample | Q3 | 2 | KG | Embeddings + inference |
| 2026 Sample | Q4 | 2 | Robot Soccer | List strategies |
| 2026 Sample | Q5 | 3 | Random Forest | Feature bagging |
| 2026 Sample | Q6 | 4 | Vagueness vs Uncertainty | Classify 4 scenarios |
| 2024 Final | Q1 | 4 | Continual Learning | Concept drift + replay |
| 2024 Final | Q2 | 3 | Search | BFS vs UCS |
| 2024 Final | Q3 | 3 | MCTS | UCB1 formula |
| 2024 Final | Q4 | 1 | RL | State/action/policy/reward |
| 2024 Final | Q5 | 2 | GNN | Permutation invariance |
| 2024 Final | Q6 | 2 | Self-Supervised | Pretext vs downstream |