📚 Year 10 OCR Computer Science: Case Study Practical Drills | 10年级 OCR 计算机科学：案例分析实战演练
Case study questions appear frequently in OCR GCSE Computer Science exams—they test your ability to apply knowledge to real-world scenarios. This article gives you ten practical drills, each with a scenario, breakdown, and model analysis. By working through them, you will strengthen your understanding of key topics and build confidence for Papers 1 and 2.
案例分析题在OCR GCSE计算机科学考试中经常出现——它们考察你将知识应用于真实场景的能力。本文提供十个实战演练，每个都包含情景、分解和示范分析。通过逐一练习，你将加深对关键主题的理解，并为试卷一和试卷二树立信心。
1. How to Approach Case Studies | 如何应对案例分析
Before diving into specific topics, it is important to have a clear strategy. Start by identifying the key domain (e.g. networks, data representation, ethics). Highlight the given facts, constraints, and requirements. Then structure your answer: define technical terms, apply relevant theory, and justify your recommendations. Use precise language and, where appropriate, include calculations or diagrams in your thinking. In a written answer, show logical steps.
在深入具体主题之前，掌握清晰的策略很重要。首先识别关键领域（例如网络、数据表示、伦理）。标出给定的事实、约束条件和需求。然后组织你的答案：定义技术术语，应用相关理论，并论证你的建议。使用精确的语言，并在适当的时候在思考中包含计算或图示。在书面答案中展示逻辑步骤。
Let’s apply this method in the drills that follow. Each drill mimics a short exam-style case study.
让我们在下面的演练中应用这个方法。每个演练都模拟一道短考试风格的案例分析题。
2. Data Representation: Image File Size | 数据表示：图像文件大小
Scenario: A graphic designer needs to upload a 24-bit colour image for a website. The image dimensions are 1920 × 1080 pixels. The website advises that images should not exceed 2 MB. Calculate the uncompressed file size of the image and advise whether compression is needed. Explain the difference between lossy and lossless compression in this context.
情景： 一位平面设计师需要为网站上传一张24位色彩的图像。图像尺寸为1920 × 1080像素。网站建议图像不应超过2 MB。计算图像未经压缩的文件大小，并建议是否需要压缩。解释在该背景下有损压缩和无损压缩的区别。
Analysis: File size (bits) = width × height × colour depth. Colour depth = 24 bits. So size = 1920 × 1080 × 24 bits. Calculate: 1920 × 1080 = 2,073,600 pixels. Multiply by 24 = 49,766,400 bits. Convert to bytes (divide by 8): 6,220,800 bytes. Convert to MB: 6,220,800 ÷ 1,048,576 ≈ 5.93 MB. This exceeds the 2 MB limit. Compression is required. Lossy compression (e.g. JPEG) would reduce file size by discarding some data, potentially lowering quality, but suitable for photos. Lossless (e.g. PNG) preserves all data but may not reduce size enough. For a photo, lossy is acceptable.
分析： 文件大小（位）= 宽度 × 高度 × 色彩深度。色彩深度 = 24位。因此大小 = 1920 × 1080 × 24 位。计算：1920 × 1080 = 2,073,600像素。乘以24 = 49,766,400位。转换为字节（除以8）：6,220,800字节。转换为MB：6,220,800 ÷ 1,048,576 ≈ 5.93 MB。这超过了2 MB的限制。需要压缩。有损压缩（如JPEG）会通过丢弃一些数据来减小文件大小，可能降低质量，但适合照片。无损压缩（如PNG）保留所有数据，但可能无法将大小减少到足够程度。对于照片，有损压缩是可接受的。
Table of common units:
| Unit | Value in bytes | 中文 |
|---|---|---|
| 1 KB | 10³ bytes | 千字节 |
| 1 MB | 10⁶ bytes | 兆字节 |
| 1 MiB | 2²⁰ bytes | 兆字节（二进制） |
Note: Operating systems often use binary multiples; network speeds use decimal. Clarify in your answers.
注意：操作系统通常使用二进制倍数；网络速度使用十进制。在你的答案中说明清楚。
3. Network Topology: School Network Design | 网络拓扑：学校网络设计
Scenario: A secondary school plans to install a new LAN across three buildings. Budget is limited, and faults must be easy to locate. The school has 200 workstations. Evaluate the suitability of star and mesh topologies, and recommend one with justification.
情景： 一所中学计划在三栋建筑间安装新的局域网。预算有限，且故障必须易于定位。学校有200个工作站。评估星形和网状拓扑的适用性，并推荐一种，同时给予论证。
In a star topology, each workstation connects to a central switch. Fault isolation is simple—if one cable fails, only that device is affected. Cost is moderate: switches are needed but cabling is manageable. Performance is good unless the switch becomes a bottleneck. A mesh topology would require each device to connect to many others, impractical for 200 devices; cabling and maintenance costs would be extremely high. Full mesh offers redundancy but is unnecessary here. Therefore, a star topology is recommended. For inter-building connection, fibre optic cables can link switches. Additional switches can create an extended star.
在星形拓扑中，每台工作站连接到一个中央交换机。故障隔离简单——如果某条电缆故障，只有该设备受影响。成本适中：需要交换机，但布线是可控的。性能良好，除非交换机成为瓶颈。网状拓扑要求每个设备连接到许多其他设备，对于200个设备不切实际；布线和维护成本极高。全互联网状提供冗余，但在该场景下没必要。因此，推荐星形拓扑。对于建筑之间的连接，光纤可以连接交换机。额外的交换机可构成扩展星形。
4. Protocols: Requesting a Web Page | 协议：请求网页
Scenario: A student types https://www.tutorhao.com into a browser. Describe the protocol stack involved in loading the page, focusing on the transport and application layers. Mention TCP/IP and HTTP/HTTPS.
情景： 一名学生在浏览器中输入 https://www.tutorhao.com。描述加载页面所涉及的协议栈，聚焦传输层和应用层。提及TCP/IP和HTTP/HTTPS。
The browser uses HTTPS (HTTP over TLS/SSL) for encrypted communication. The application layer protocol is HTTP, secured by TLS. The hostname is resolved to an IP address via DNS, which uses UDP or TCP on port 53. Then a TCP connection is established to the server on port 443 (HTTPS). TCP provides reliable, ordered data delivery. The three-way handshake occurs, then HTTP GET request is sent. The server responds with the webpage data. Throughout, IP handles routing. So the stack: Application (HTTP/HTTPS), Transport (TCP), Internet (IP), Network Access.
浏览器使用HTTPS（TLS/SSL上的HTTP）进行加密通信。应用层协议是HTTP，由TLS保证安全。主机名通过DNS解析为IP地址，DNS使用UDP或TCP，端口53。然后与服务器建立TCP连接，端口443（HTTPS）。TCP提供可靠、有序的数据传递。经过三次握手，发送HTTP GET请求。服务器以网页数据响应。整个过程中，IP处理路由。因此协议栈：应用层（HTTP/HTTPS）、传输层（TCP）、网络层（IP）、网络接入层。
5. Cybersecurity: Preventing SQL Injection | 网络安全：防止SQL注入
Scenario: A school’s online portal allows students to view their timetable by entering a student ID. The back-end database uses SQL. The current code concatenates the input directly into a query. Explain the risk and suggest two methods to mitigate it.
情景： 学校门户网站允许学生通过输入学号查看他们的课表。后端数据库使用SQL。当前代码直接将输入拼接到查询中。解释风险，并提出两种缓解方法。
Risk: SQL injection. An attacker can enter a specially crafted input like 105 OR 1=1 to manipulate the query, potentially exposing all records or deleting data. This occurs because user input is treated as part of the SQL command. Mitigation 1: parameterised queries (prepared statements) – the query structure is defined first, and inputs are bound as parameters, thus never interpreted as code. Mitigation 2: input validation – enforce strict patterns (e.g. only digits for student ID) and escape special characters. However, parameterised queries are the most robust defence.
风险：SQL注入。攻击者可以输入特制的输入，例如 105 OR 1=1，操纵查询，可能暴露所有记录或删除数据。发生这种情况是因为用户输入被视为SQL命令的一部分。缓解方法1：参数化查询（预编译语句）——先定义查询结构，然后将输入绑定为参数，因此绝不会被解释为代码。缓解方法2：输入验证——强制执行严格模式（例如学号只能是数字），并转义特殊字符。然而，参数化查询是最坚固的防御。
6. System Software: Choosing an OS for a Kiosk | 系统软件：为自助服务终端选择操作系统
Scenario: A museum wants an interactive kiosk running a single touch-screen application to show floor plans. The kiosk should boot quickly, be secure, and require minimal maintenance. Evaluate two types of operating systems: a full multi-user OS (like Windows) versus a lightweight embedded OS. Recommend one.
情景： 一家博物馆需要一个交互式自助服务终端，运行一个显示楼层平面图的触摸屏应用程序。该终端需要快速启动、安全，且维护量极小。评估两类操作系统：完整的多用户操作系统（如Windows）与轻量级嵌入式操作系统。推荐一种。
A full OS offers many features (multitasking, user accounts) but these are unnecessary and increase boot time, attack surface, and update frequency. An embedded OS (e.g. a stripped-down Linux or a real-time OS) can be customised to launch only the needed application. It boots faster, has fewer security vulnerabilities due to minimal components, and requires fewer updates. For a dedicated kiosk, an embedded OS is preferable. It also reduces hardware cost because it can run on lower-spec processors.
一个完整的
Published by TutorHao | Year 10 Computer Science Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导Cancel reply