📚 IB & OCR Computer Science End-of-Term Revision Outline | IB与OCR计算机科学期末复习提纲
As the end of term approaches, students preparing for the IB Diploma Computer Science or OCR A Level Computer Science examinations need a structured and efficient revision plan. This outline consolidates the core theoretical and practical topics common to both syllabi, including data representation, hardware, networks, programming, algorithms, and societal implications. Use this checklist to identify strengths, address gaps, and build confidence before the final assessments.
随着期末临近，备战IB文凭计算机科学或OCR A Level计算机科学考试的学生需要一份系统高效的复习计划。本提纲融合了两套课程体系共有的核心理论与实践主题，涵盖数据表示、硬件、网络、编程、算法及社会影响。请用这份清单查漏补缺，建立考前信心。
1. Data Representation | 数据表示
Understand how binary numbers represent data, including positive integers, negative numbers using two's complement, and floating point representation. Be able to convert between binary, denary, and hexadecimal effortlessly.
理解二进制如何表示数据，包括正整数、用补码表示的负数以及浮点表示。要能熟练地在二进制、十进制和十六进制间转换。
For character encoding, revise ASCII and Unicode, explaining how code points are mapped to characters and the difference between UTF-8, UTF-16, and UTF-32. Discuss the relationship between storage requirements and character sets.
对于字符编码，复习ASCII和Unicode，解释码点如何映射到字符，以及UTF-8、UTF-16和UTF-32的差异。讨论存储需求与字符集的关系。
Study image and sound representation: bitmap vs vector graphics, colour depth, resolution, sampling rate, and bit rate. Calculate file sizes for image and audio files using given parameters.
学习图像和声音的表示：位图与矢量图、色彩深度、分辨率、采样率和比特率。根据给定参数计算图像和音频文件的文件大小。
Data compression is essential: distinguish between lossy and lossless compression, and describe common algorithms such as run-length encoding (RLE), Huffman coding, and dictionary-based methods like LZW.
数据压缩至关重要：区分有损和无损压缩，并描述常见算法，如游程编码（RLE）、哈夫曼编码和基于字典的方法如LZW。
Two's complement of −x = (2ⁿ − x) in binary, where n = number of bits.
−x 的补码（二进制）= 2ⁿ − x，其中 n 为位数。
2. Computer Architecture & Hardware | 计算机体系结构与硬件
Recall the von Neumann architecture: a single shared memory for instructions and data, with a central processing unit (CPU) containing the arithmetic logic unit (ALU), control unit (CU), and registers (PC, MAR, MDR, ACC).
回顾冯·诺依曼体系结构：指令和数据共享同一内存，中央处理器（CPU）包含算术逻辑单元（ALU）、控制单元（CU）和寄存器（PC、MAR、MDR、ACC）。
Explain the fetch–decode–execute cycle in detail, describing the role of the address bus, data bus, and control bus. Link this to factors affecting CPU performance: clock speed, number of cores, and cache memory.
详细说明取指–译码–执行周期，描述地址总线、数据总线和控制总线的作用。将其与影响CPU性能的因素联系起来：时钟速度、核心数量和高速缓存。
Secondary storage devices differ in technology: magnetic (HDD), optical (CD/DVD/Blu-ray), and solid state (SSD). Compare them in terms of speed, durability, capacity, and cost. Understand virtual storage and cloud storage concepts.
辅助存储设备技术各异：磁性（HDD）、光学（CD/DVD/蓝光）和固态（SSD）。从速度、耐用性、容量和成本方面进行比较。理解虚拟存储和云存储概念。
Input and output devices should also be revised, including sensors, touch screens, barcode readers, and actuators. Focus on how they interact with the system via interrupts and polling.
同时复习输入输出设备，包括传感器、触摸屏、条码扫描器和执行器。关注它们如何通过中断和轮询与系统交互。
3. Operating Systems & System Software | 操作系统与系统软件
An operating system manages hardware resources, provides a user interface, and enables multitasking. Revise memory management (paging, segmentation, virtual memory), process scheduling (round robin, priority scheduling), and file management.
操作系统管理硬件资源、提供用户界面并实现多任务处理。复习内存管理（分页、分段、虚拟内存）、进程调度（轮询、优先级调度）和文件管理。
Describe the role of the OS in ensuring security and access control, handling interrupts, and providing an application programming interface (API) for software developers.
描述操作系统在确保安全和访问控制、处理中断以及为软件开发人员提供应用程序接口（API）方面的作用。
Utility software includes disk defragmenters, antiviral tools, backup software, and compression utilities. Know how each contributes to system maintenance and efficiency.
实用软件包括磁盘碎片整理程序、防病毒工具、备份软件和压缩工具。了解它们各自如何促进系统维护和效率。
Firmware and boot processes: understand the role of BIOS/UEFI, the boot sequence, and how the OS kernel is loaded into memory.
固件与启动过程：理解BIOS/UEFI的作用、启动顺序以及操作系统内核如何被加载到内存。
4. Networks & Communication | 网络与通信
Networks are classified by scale: LAN, MAN, WAN, PAN. Remember topologies (star, mesh, bus, ring) and their advantages and disadvantages in terms of reliability, cost, and performance.
网络按规模分类：LAN、MAN、WAN、PAN。记住拓扑结构（星型、网状、总线、环形）及其在可靠性、成本和性能方面的优缺点。
Master the TCP/IP protocol stack: application, transport, internet, and network access layers. Compare with the OSI model and explain the function of protocols such as HTTP, HTTPS, FTP, SMTP, POP3, TCP, UDP, and IP.
掌握TCP/IP协议栈：应用层、传输层、互联网层和网络接入层。与OSI模型对比，解释HTTP、HTTPS、FTP、SMTP、POP3、TCP、UDP和IP等协议的功能。
IP addressing: differentiate IPv4 and IPv6, understand subnet masks, and describe the purpose of DNS in translating domain names to IP addresses. Explain the role of routers, switches, and gateways.
IP寻址：区分IPv4和IPv6，理解子网掩码，描述DNS在将域名转换为IP地址中的作用。解释路由器、交换机和网关的角色。
Wireless networking technologies, including Wi-Fi and Bluetooth, and their security protocols (WPA2, WPA3). Discuss packet switching, circuit switching, and how data packets travel across a network.
无线网络技术，包括Wi-Fi和蓝牙，以及它们的安全协议（WPA2、WPA3）。讨论分组交换、电路交换以及数据包如何在网络中传输。
ata transferred / Time taken. Keep in mind the impact of latency, jitter, and packet loss.
吞吐量 = 传输的数据量 / 所用时间。牢记延迟、抖动和丢包的影响。
5. Databases & Information Systems | 数据库与信息系统
Relational databases store data in tables with primary keys, foreign keys, and constraints. Revise normalization to 3NF and, for IB, the role of the Entity–Relationship (ER) model in conceptual design.
关系数据库将数据存储在具有主键、外键和约束的表中。复习第三范式（3NF）规范化，并针对IB，理解实体–关系（ER）模型在概念设计中的作用。
Practice writing SQL queries: SELECT, FROM, WHERE, JOIN (INNER, LEFT, RIGHT), GROUP BY, HAVING, ORDER BY, and aggregate functions (COUNT, SUM, AVG). Be prepared to write queries for given scenarios.
练习编写SQL查询：SELECT、FROM、WHERE、JOIN（INNER、LEFT、RIGHT）、GROUP BY、HAVING、ORDER BY以及聚合函数（COUNT、SUM、AVG）。准备好根据给定情景编写查询。
Transaction processing and ACID properties (Atomicity, Consistency, Isolation, Durability) ensure data integrity. Explain concurrency control and the need for locking and timestamps.
事务处理与ACID特性（原子性、一致性、隔离性、持久性）确保数据完整性。解释并发控制以及锁定和时间戳的必要性。
Discuss the importance of data warehousing and data mining for business intelligence, and the ethical implications of large-scale data collection.
讨论数据仓储和数据挖掘对商业智能的重要性，以及大规模数据收集的伦理影响。
6. Algorithms & Problem Solving | 算法与问题求解
Algorithms are expressed through flowcharts, pseudocode, or natural language. Revise fundamental concepts: sequence, selection (IF-THEN-ELSE), iteration (FOR, WHILE loops), and recursion.
算法用流程图、伪代码或自然语言表达。复习基本概念：顺序、选择（IF-THEN-ELSE）、迭代（FOR、WHILE循环）和递归。
Searching algorithms: linear search O(n) and binary search O(log n). Sorting algorithms: bubble sort, insertion sort, merge sort, and quicksort. Know each algorithm's time complexity and when it is most efficient.
查找算法：线性查找 O(n) 和二分查找 O(log n)。排序算法：冒泡排序、插入排序、归并排序和快速排序。了解每种算法的时间复杂度及何时最高效。
Be able to trace an algorithm step by step using a trace table, identifying variables, conditions, and output. This is critical for both IB and OCR written exams.
要能使用跟踪表逐步跟踪算法，识别变量、条件和输出。这对IB和OCR的笔试都至关重要。
Standard algorithms: arrays, such as finding maximum/minimum, counting occurrences, and linear search. Also revise the use of stacks (push, pop) and queues (enqueue, dequeue) in abstract data types.
标准算法：数组，如找最大值/最小值、计数出现次数和线性查找。同时复习栈（入栈、出栈）和队列（入队、出队）等抽象数据类型的使用。
7. Programming & Software Development | 编程与软件开发
Programming paradigms: procedural, object-oriented (encapsulation, inheritance, polymorphism), and functional. Understand how abstraction and decomposition are applied in solving complex problems.
编程范式：过程式、面向对象（封装、继承、多态）和函数式。理解抽象和分解如何在解决复杂问题中应用。
Data types: integer, real/float, Boolean, character, string, and arrays. Know how to declare variables, assign values, and use built-in functions for string manipulation and type conversion.
数据类型：整型、实型/浮点型、布尔型、字符型、字符串和数组。掌握如何声明变量、赋值以及使用字符串操作和类型转换的内置函数。
Testing and debugging: white-box testing, black-box testing, unit testing, integration testing, and alpha/beta testing. Use test plans with normal, boundary, and erroneous data to ensure robustness.
测试与调试：白盒测试、黑盒测试、单元测试、集成测试以及α/β测试。使用包含正常、边界和错误数据的测试计划确保程序的健壮性。
Version control and documentation are part of professional practice. In IB's Internal Assessment and OCR's Programming Project, you must produce clear code comments, user documentation, and an evaluation.
版本控制和文档是专业实践的一部分。在IB的内部评估和OCR编程项目中，你必须提供清晰的代码注释、用户文档和评估报告。
8. Data Structures & Abstract Data Types | 数据结构与抽象数据类型
Arrays (one-dimensional, two-dimensional) store elements of the same type in contiguous memory. Linked lists (singly, doubly) use nodes with pointers to dynamically allocate memory.
数组（一维、二维）在连续内存中存储相同类型的元素。链表（单向、双向）使用带有指针的节点动态分配内存。
Stacks are LIFO structures useful for backtracking, undo operations, and expression evaluation. Queues are FIFO and used for scheduling, buffers, and breadth-first search.
栈是后进先出（LIFO）结构，适用于回溯、撤销操作和表达式求值。队列是先进先出（FIFO），用于调度、缓冲区和广度优先搜索。
Trees: binary trees, binary search trees (BST), and tree traversal (pre-order, in-order, post-order). Understand hashing and hash tables for O(1) average lookup time, including collision resolution strategies.
树：二叉树、二叉搜索树（BST）以及树的遍历（前序、中序、后序）。理解哈希和哈希表实现 O(1) 平均查找时间，包括冲突解决策略。
For IB Higher Level, revise object references and the concept of dynamic data structures, and for OCR, be familiar with how these structures are implemented in a low-level language context.
对于IB高级课程，复习对象引用和动态数据结构概念；对于OCR，要熟悉这些结构如何在低级语言环境中实现。
9. Computational Thinking & Ethics | 计算思维与伦理
Computational thinking involves decomposition, pattern recognition, abstraction, and algorithm design. Apply these skills to analyze a problem before writing any code.
计算思维包含分解、模式识别、抽象和算法设计。在编写任何代码之前，先用这些技能分析问题。
Social and ethical issues: intellectual property, data privacy, cybersecurity, digital divide, artificial intelligence bias, and the environmental impact of computing (e-waste, energy consumption).
社会与伦理议题：知识产权、数据隐私、网络安全、数字鸿沟、人工智能偏见以及计算的环境影响（电子垃圾、能耗）。
Privacy laws and regulations such as UK GDPR and Data Protection Act must be understood. Discuss the responsibilities of data collectors and the rights of data subjects.
必须理解UK GDPR和数据保护法等隐私法规。讨论数据收集者的责任和数据主体的权利。
Both IB and OCR assessments include extended response questions requiring well-reasoned arguments. Support your views with relevant examples, such as the use of facial recognition or smart city technology.
IB和OCR的考核都包含需要严密论证的简答题。用相关实例支撑你的观点，例如人脸识别或智慧城市技术的应用。
10. Exam Preparation Strategies | 备考策略
For IB Computer Science, Paper 1 tests core topics; Paper 2 focuses on the chosen option (e.g., databases, web science, or OOP); Paper 3 is the case study, and the IA is a practical project. Ensure you understand the mark schemes and command terms (describe, explain, evaluate).
IB计算机科学考试中，试卷一考查核心主题；试卷二集中于所选模块（如数据库、网络科学或面向对象编程）；试卷三是案例研究，内部评估（IA）是实践项目。务必理解评分方案和指令性术语（描述、解释、评价）。
For OCR A Level, Component 01 covers computer systems, Component 02 algorithms and programming, Component 03 is the programming project, and there is also the re-created Component 04 for exam series. Practice past papers under timed conditions and review examiner reports.
OCR A Level考试中，组件一涵盖计算机系统，组件二为算法与编程，组件三是编程项目，考试系列还包括重组的组件四。定时练习历年真题并查阅考官报告。
Create concise revision notes, mind maps, and flashcards for key definitions. Teach a concept to a peer or explain it aloud to reinforce memory.
整理简洁的复习笔记、思维导图和关键定义的闪卡。试着向同伴讲解一个概念或大声解释以巩固记忆。
Balance theory with practical coding. Write short programs implementing data structures or algorithms from scratch, and break down large problems into manageable subtasks using stepwise refinement.
兼顾理论与实践编码。编写简短的、从头实现数据结构或算法的程序，并使用逐步求精将大问题分解为可管理的子任务。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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