KS3 Cambridge Computing: Key Points for Practical Assessments | KS3 Cambridge 计算机：实验/实践考核要点

📚 KS3 Cambridge Computing: Key Points for Practical Assessments | KS3 Cambridge 计算机：实验/实践考核要点

Practical assessments in KS3 Cambridge Computing give you the chance to demonstrate what you can actually do: designing solutions, writing code, manipulating data, building digital artefacts and reflecting on your work. Understanding exactly what examiners look for — from clear planning to rigorous testing — will help you turn your skills into top marks.

KS3 Cambridge 计算机的实践考核让你有机会展示你真正能做什么：设计解决方案、编写代码、操作数据、构建数字制品以及反思你的工作。清楚了解考官看重什么——从清晰的规划到严格的测试——将帮助你把技能转化为高分。

1. Understanding Practical Assessment Criteria | 理解实践考核标准

Most practical tasks are marked against several strands: planning and design, implementation, testing and evaluation. You need to show evidence for each strand. For example, before you start coding, sketch a flowchart or write pseudocode to prove you have thought about the structure of your solution.

大多数实践任务按几个方面评分：规划与设计、实现、测试和评价。你需要为每个方面提供证据。例如，在开始编码之前，画一个流程图或写一段伪代码，证明你已经思考过解决方案的结构。

Documentation is not an afterthought. Keep notes or use comments in your code to explain why you made certain choices. In Scratch, use the ‘say’ blocks or comment boxes; in Python, use # comments.

文档记录不是事后才做的事。保留笔记或在代码中使用注释来解释你为什么做出某些选择。在 Scratch 中使用 ‘say’ 积木或注释框；在 Python 中使用 # 注释。

Evaluation is also part of the criteria. You should compare your final product against your original success criteria, describe what worked well and identify at least one improvement you would make if you had more time.

评价也是评分标准的一部分。你应该将最终产品与最初的成功标准进行比较，描述哪些方面做得不错，并指出如果时间更充裕你至少会做的一项改进。

---

2. Algorithm Design and Flowcharts | 算法设计与流程图

An algorithm is a step-by-step sequence of instructions to solve a problem. In the assessment, you may be asked to design an algorithm before coding. Always break the problem down into smaller, manageable steps — this is called decomposition.

算法是解决某个问题的一步一步的指令序列。在考核中，你可能会被要求在编码前设计算法。始终将问题分解为更小、更易处理的步骤——这称为分解。

Flowchart symbols must be drawn accurately. Use ovals for Start/End, parallelograms for Input/Output, rectangles for processes, diamonds for decisions, and arrows to show the flow. Practice drawing them by hand so you can reproduce them quickly under time pressure.

流程图符号必须准确绘制。使用椭圆形表示开始/结束，平行四边形表示输入/输出，矩形表示处理过程，菱形表示判断，箭头表示流程方向。练习手工绘制，以便在时间压力下也能快速画出。

English Point	中文要点
Oval: Start or End of the program	椭圆形：程序开始或结束
Parallelogram: Input or Output (e.g., ‘Enter age’)	平行四边形：输入或输出（如“输入年龄”）
Rectangle: Process (e.g., calculate total)	矩形：处理过程（如计算总和）
Diamond: Decision (yes/no question)	菱形：判断（是/否问题）

Pseudocode is another way to plan. It uses plain English-like statements without worrying about exact syntax. For example: ‘INPUT password’, ‘IF password equals “secret” THEN OUTPUT “Access granted” ELSE OUTPUT “Denied”‘. Make sure your pseudocode shows sequence, selection and iteration clearly.

伪代码是另一种规划方式。它使用类似普通英语的语句，不用在意精确语法。例如：“输入密码”，“如果密码等于 “secret” 那么输出 “允许访问” 否则输出 “拒绝””。确保你的伪代码清晰展示顺序、选择和循环。

---

3. Coding with Scratch or Python | 用 Scratch 或 Python 编程

You will be assessed on your ability to use the three building blocks of programming: sequence (instructions in order), selection (if/else decisions) and iteration (loops like repeat, while, for). Even a simple interactive game must include all three.

你将接受使用编程三大构建模块能力的评估：顺序（按顺序执行的指令）、选择（if/else 判断）和循环（如 repeat、while、for 循环）。即使是一个简单的交互游戏也必须包含这三者。

Variables are containers that store data. Give your variables meaningful names, like ‘score’ or ‘player_name’, not just ‘x’. In Scratch you can create variables using the ‘Variables’ palette; in Python you simply assign a value: score = 0.

变量是存储数据的容器。给你的变量取有意义的名字，如 ‘score’ 或 ‘player_name’，而不仅仅是 ‘x’。在 Scratch 中，你可以使用“变量”面板创建变量；在 Python 中，直接赋值即可：score = 0。

You must handle user input and use conditional statements correctly. In Python, remember the colon after the condition and indentation. For example:

if age >= 18:
  print(“You can vote”)
else:
  print(“Too young”)

你必须正确处理用户输入并使用条件语句。在 Python 中，记住条件后要有冒号并正确缩进。例如：如果 age >= 18 则输出 “你可以投票”，否则输出 “太年轻”。

Logical operators (AND, OR, NOT) allow you to combine conditions. In a practical task, you might need to check if username equals ‘admin’ AND password equals ‘1234’ to grant access. Test these combinations carefully.

逻辑运算符（AND、OR、NOT）允许你组合条件。在实践任务中，你可能需要检查用户名是否等于 ‘admin’ 并且密码是否等于 ‘1234’ 来授予访问权限。仔细测试这些组合。

---

4. Debugging and Error Handling | 调试与错误处理

Errors are inevitable, and the examiner wants to see how you find and fix them. Syntax errors occur when you break the language rules, such as missing a colon or a closing bracket. Read error messages carefully — they often tell you the line number and type of mistake.

错误是难免的，考官想看到你如何发现并修复它们。当你违反语言规则时会出现语法错误，例如少了一个冒号或右括号。仔细阅读错误信息——它们通常会告诉你错误所在的行号和错误类型。

Logical errors are trickier: the program runs but produces wrong results. Use a trace table to track the values of variables as you step through the algorithm. If a scoring system keeps giving double points, the logic is probably adding twice somewhere.

逻辑错误更为棘手：程序能运行但产生错误结果。使用追踪表在你逐步执行算法时跟踪变量值的变化。如果计分系统总是给出双倍分数，逻辑上很可能在某处重复加了两次。

Testing should be systematic, not random. Create a simple test plan with input data, expected outcome and actual outcome. For a calculator program, test normal values (5 + 3 = 8), boundary values (dividing by very small numbers) and invalid data (entering text instead of a number).

测试应当系统化，而非随意进行。创建一个简单的测试计划，包含输入数据、预期结果和实际结果。对于一个计算器程序，要测试正常值（5 + 3 = 8）、边界值（除以非常小的数字）和无效数据（输入文本而非数字）。

---

5. Using Spreadsheets for Data Modelling | 使用电子表格进行数据建模

Spreadsheets are powerful tools for handling numbers and creating models. You must be able to enter data, format cells, and write formulas. Basic functions like SUM, AVERAGE, MIN and MAX are frequently assessed.

电子表格是处理数字和创建模型的强大工具。你必须能够输入数据、设置单元格格式并编写公式。像 SUM、AVERAGE、MIN 和 MAX 这样的基本函数经常会被考核。

Understanding cell referencing is crucial. Relative references (e.g., A1) change when you copy a formula down a column, while absolute references (e.g., $A$1) stay fixed. In a practical task where you apply a tax rate stored in one cell, you should use an absolute reference to that cell so the formula can be filled correctly.

理解单元格引用至关重要。相对引用（如 A1）在向下复制公式时会发生变化，而绝对引用（如 $A$1）保持不变。在应用存储于某个单元格的税率的实践任务中，你应该对该单元格使用绝对引用，这样公式才能被正确填充。

You may be asked to create a chart. Select the correct data range, choose an appropriate chart type (bar for comparisons, line for trends, pie for proportions), and include clear labels and a title. Make sure the chart supports the story your data tells.

你可能会被要求创建图表。选择正确的数据区域，选择合适的图表类型（条形图用于比较，折线图用于趋势，饼图用于比例），并包含清晰的标签和标题。确保图表能够支持你的数据所要展现的内容。

---

6. Database Creation and Querying | 数据库创建与查询

In database tasks you will need to set up a flat-file database with appropriate fields and data types. Common data types include text, number, date/time and Boolean (yes/no). Choose the type that best matches the data, and set a primary key to uniquely identify each record.

在数据库任务中，你需要用合适的字段和数据类型建立一个平面文件数据库。常见的数据类型包括文本、数字、日期/时间和布尔型（是/否）。选择与数据最匹配的类型，并设置主键来唯一标识每条记录。

Queries let you extract specific information. You might use a query-by-example grid to filter records, e.g., find all students with ‘House = Blue’ AND ‘Points > 50’. Alternatively, you could be asked to write a simple SQL statement: SELECT * FROM Students WHERE House = ‘Blue’ AND Points > 50;.

查询让你能够提取特定信息。你可能会使用范例查询网格来筛选记录，例如，找出所有“学院 = 蓝”并且“积分 > 50”的学生。也可能要求你写一条简单的 SQL 语句：SELECT * FROM Students WHERE House = ‘Blue’ AND Points > 50;。

Sorting and reporting are also key skills. You should be able to sort records in ascending or descending order on one or more fields, then produce a report that presents the filtered data clearly. Always check that the report does not include unintended records.

排序和生成报表也是关键技能。你应该能够按一个或多个字段对记录进行升序或降序排序，然后生成一份清晰呈现筛选后数据的报表。始终检查报表中是否包含了不该包含的记录。

---

7. Web Page Development with HTML | 用 HTML 开发网页

You may be asked to create a simple web page using HTML tags. The basic structure includes ,

(with sections. Make sure every opening tag has a corresponding closing tag — a common mistake is forgetting

or