IB Computer Science HL · Year 2

Interactive Lesson Library

55 self-contained lessons for first assessment 2027. Open lessons online or download individual lessons for offline study.

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Internal Assessment

Criteria A–E, course checkpoints, word-count guidance, video/appendix requirements, authenticity and final submission checklist.

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Paper 1 Section B

2027 Case Study

Generative AI image creation: four HL challenge areas, terminology, research timeline and evidence-bank checklist.

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Programming & Computational Thinking

Lessons 1–10
Lesson 1

Computational-thinking retrieval + static/dynamic structures, arrays and lists

B1.1.1B1.1.2B1.1.3B2.1.1B2.2.1B2.2.2
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Lesson 2

Stacks: LIFO operations and trade-offs

B2.2.3
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Lesson 3

Queues: FIFO operations and trade-offs

B2.2.4
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Lesson 4

Sequence and selection

B2.3.1B2.3.2
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Lesson 5

Loops, functions, modularization and scope

B2.1.2B2.3.3B2.3.4
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Lesson 6

Flowchart/algorithmic-thinking retrieval + algorithm efficiency and Big O

B1.1.4B2.4.1
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Lesson 7

Linear and binary search

B2.4.2
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Lesson 8

Bubble and selection sort

B2.4.3
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Lesson 9

Recursion: concepts, tracing and construction

B2.4.4B2.4.5
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Lesson 10

Exception handling, debugging, file processing + B2 Paper 2 checkpoint

B2.1.3B2.1.4B2.5.1B2.1.1B2.1.2B2.2.1B2.2.2B2.2.3
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Object-Oriented Programming

Lessons 11–20
Lesson 11

OOP foundations + UML class design

B3.1.1B3.1.2
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Lesson 12

Static/instance members, constructors and object creation

B3.1.3B3.1.4
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Lesson 13

Encapsulation and information hiding

B3.1.5
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Lesson 14

Single-class OOP applied design/programming

B3.1.1B3.1.2B3.1.3B3.1.4B3.1.5
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Lesson 15

B3.1 cumulative Paper 2 checkpoint

B3.1.1B3.1.2B3.1.3B3.1.4B3.1.5
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Lesson 18

Abstraction and abstract classes

B3.2.3
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Lesson 19

Aggregation vs composition

B3.2.4
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Lesson 20

Design patterns + B3.2 checkpoint

B3.2.5B3.2.1B3.2.2B3.2.3B3.2.4
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Abstract Data Types

Lessons 21–28
Lesson 21

ADTs + linked-list evaluation

B4.1.1B4.1.2
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Lesson 23

Doubly and circular linked lists

B4.1.3
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Lesson 24

Linked-list operations and applications

B4.1.2B4.1.3
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Lesson 25

Binary search trees: structure and insertion

B4.1.4
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Lesson 26

BST operations, traversal and evaluation

B4.1.4
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Lesson 28

Hash tables + B4 cumulative Paper 2 checkpoint

B4.1.6B4.1.1B4.1.2B4.1.3B4.1.4B4.1.5
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Computer Fundamentals

Lessons 29–37
Lesson 29

CPU architecture, memory and fetch-decode-execute

A1.1.1A1.1.4A1.1.5
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Lesson 30

Secondary storage, compression and cloud services

A1.1.7A1.1.8A1.1.9
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Lesson 31

Binary/hex and binary data representation

A1.2.1A1.2.2
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Lesson 32

Logic gates, truth tables, Karnaugh maps and logic diagrams

A1.2.3A1.2.4A1.2.5
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Lesson 33

Operating systems: roles, functions and scheduling

A1.3.1A1.3.2A1.3.3
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Lesson 34

Polling/interrupts, multitasking and resource allocation

A1.3.4A1.3.5
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Lesson 35

Control systems

A1.3.6A1.3.7
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Lesson 36

Compilers, interpreters, JIT and bytecode

A1.4.1
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Lesson 37

CPU/GPU, pipelining + A1 Paper 1 synthesis

A1.1.2A1.1.3A1.1.6A1.1.1A1.1.4A1.1.5A1.1.7A1.1.8
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Networks

Lessons 38–42
Lesson 38

Network purpose, types and digital infrastructures

A2.1.1A2.1.2
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Lesson 39

Network devices, protocols and TCP/IP model

A2.1.3A2.1.4A2.1.5
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Lesson 40

Topologies, servers, network models and segmentation

A2.2.1A2.2.2A2.2.3A2.2.4
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Lesson 41

IP addressing, media, packet switching and routing

A2.3.1A2.3.2A2.3.3A2.3.4
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Lesson 42

Network security + A2 Paper 1 synthesis

A2.4.1A2.4.2A2.4.3A2.4.4A2.1.1A2.1.2A2.1.3A2.1.4
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Databases

Lessons 43–49
Lesson 43

Relational databases + database schemas

A3.1.1A3.2.1
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Lesson 44

ERDs, data types and relational table construction

A3.2.2A3.2.3A3.2.4
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Lesson 45

Normalization to 3NF and denormalization

A3.2.5A3.2.6A3.2.7
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Lesson 46

SQL languages, queries and updates

A3.3.1A3.3.2A3.3.3
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Lesson 47

Aggregates, views and ACID transactions

A3.3.4A3.3.5A3.3.6
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Lesson 48

Alternative databases + data warehouses

A3.4.1A3.4.2
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Lesson 49

OLAP, data mining and distributed databases + A3 synthesis

A3.4.3A3.4.4A3.1.1A3.2.1A3.2.2A3.2.3A3.2.4A3.2.5
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Machine Learning & 2027 Case Study

Lessons 50–55
Lesson 50

Machine learning types, applications and hardware

A4.1.1A4.1.2
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Lesson 51

Data preprocessing: cleaning, feature selection, dimensionality reduction

A4.2.1A4.2.2A4.2.3
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Lesson 52

Supervised learning: regression, classification and evaluation

A4.3.1A4.3.2A4.3.3
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Lesson 53

Clustering, association rules, reinforcement learning and genetic algorithms

A4.3.4A4.3.5A4.3.6A4.3.7
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Lesson 54

ANNs, CNNs and model selection

A4.3.8A4.3.9A4.3.10
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Lesson 55

Ethics retrieval + 2027 case study synthesis + final Paper 1 consolidation

A4.4.1A4.4.2A4.1.1A4.1.2A4.2.1A4.2.2A4.2.3A4.3.1
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