KS3 Cambridge Statistics: Key Vocabulary Quick-Memorization Guide | KS3 Cambridge 统计：词汇术语速记指南

📚 KS3 Cambridge Statistics: Key Vocabulary Quick-Memorization Guide | KS3 Cambridge 统计：词汇术语速记指南

Statistics can feel like learning a new language when you first encounter terms like ‘categorical data’ or ‘probability’. This guide breaks down every key vocabulary word you need for KS3 Cambridge Statistics, pairing clear English explanations with Chinese translations and memory hooks. By mastering these terms, you will read questions more confidently and communicate your reasoning precisely.

初次接触统计时，‘分类数据’或‘概率’这样的术语仿佛在学一门新语言。本指南为你拆解 KS3 Cambridge 统计必须掌握的每一个核心词汇，每条术语都配有清晰的英文解释、中文翻译和记忆线索。掌握这些术语后，你会更有信心读懂题目，并能精确表达你的推理过程。

1. Data and Variables | 数据与变量

Data means any pieces of information that we collect, record and analyse. In statistics, data can be numbers, words, measurements or observations about a group. Without data, we cannot answer statistical questions.

数据是指我们收集、记录并分析的任何信息片段。在统计中，数据可以是关于一个群体的数字、文字、测量值或观察结果。没有数据，我们就无法回答统计问题。

A variable is a characteristic or property that can take on different values from one person or object to another. For example, ‘height’ is a variable because different students have different heights. The opposite of a variable is a constant, which stays the same for all cases we study.

变量是指一个特征或属性，不同的人或对象可以取不同的值。例如，‘身高’是一个变量，因为不同的学生身高不同。变量的反义词是常量，它在所有被研究个体中保持不变。

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2. Types of Data: Categorical vs Numerical | 数据类型：分类数据与数值数据

Categorical data (also called qualitative data) describes qualities or groups. It answers the question ‘what type?’ and often uses words or labels. Examples include hair colour, favourite subject, or the brand of a mobile phone. Categorical data can be ordinal if the categories have a natural order (like satisfaction ratings: poor, average, good) or nominal if there is no order (like colours).

分类数据（也称定性数据）描述性质或组别。它回答‘是什么类型？’常使用词语或标签。例如发色、最喜欢的学科或手机品牌。如果类别有自然顺序（如满意度评级：差、一般、好），则为有序分类数据；如果无顺序（如颜色），则为名义分类数据。

Numerical data (also called quantitative data) expresses amounts or quantities. It always involves numbers that can be measured or counted. Numerical data can be further split into discrete and continuous types. For instance, number of siblings is numerical, and so is the mass of a kitten.

数值数据（也称定量数据）表示数量或度量。它总是涉及可测量或可计数的数字。数值数据可进一步分为离散型和连续型。例如，兄弟姐妹的数量是数值数据，小猫的质量也是数值数据。

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3. Discrete and Continuous Data | 离散数据与连续数据

Discrete data can only take specific, separate values. Usually you get discrete data by counting. You cannot have 2.5 people in a family; it must be a whole number. Typical discrete variables are number of pets, shoe size (even half-sizes are still limited steps) and goals scored in a match.

离散数据只能取特定的、互不相连的值。通常通过计数得到。一个家庭不可能有 2.5 个人；必须是整数。典型的离散变量有宠物数量、鞋码（即使是半码，也是有限步长）和比赛进球数。

Continuous data can take any value within a range. It is usually obtained by measuring. Height, time, temperature and mass are continuous because you can have values like 1.63 m or 14.7 seconds. The precision depends on the measuring instrument, not on fixed jumps.

连续数据可以在一个范围内取任意值。通常通过测量获得。身高、时间、温度和质量都是连续的，因为你可以得到 1.63 米或 14.7 秒这样的值。精确度取决于测量工具，而不是固定的跳跃间隔。

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4. Collecting Data: Surveys and Samples | 数据收集：调查与样本

A survey is a method of gathering information by asking questions. A census is a survey that includes every member of the population. However, a census is often impractical, so we use a sample — a smaller group selected from the population. The population is the complete set of people or things we want to study.

调查是通过提问来收集信息的方法。普查是包含总体中每一个成员的调查。然而，普查通常不切实际，因此我们使用样本——从总体中选出的一个较小群体。总体是我们想要研究的全部人或事物的集合。

The sample must be representative to avoid bias. A random sample gives every member an equal chance of being chosen. When a sample is biased, the conclusions drawn about the population may be wrong. For KS3, you need to recognise whether a data collection method is fair.

样本必须具有代表性以避免偏差。随机样本让每个成员都有同等被选中的机会。当样本存在偏差时，对总体做出的推论可能错误。在 KS3 阶段，你需要能判断一种数据收集方法是否公平。

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5. Frequency and Tally Charts | 频数与计数表

Frequency is simply the number of times something occurs. When you organise raw data, you often count how many data points fall into each category or interval. A tally chart uses marks like |||| (a group of five is shown as |||| with a diagonal cross through it) to record frequency during an experiment or survey.

频数就是某事物发生的次数。当你整理原始数据时，通常会统计每个类别或区间有多少数据点。计数表使用诸如 |||| 的记号（五条为一组，用斜线划在一起）在实验或调查过程中记录频数。

Once tallied, the results are displayed in a frequency table. The table lists each category next to its frequency. In grouped frequency tables for continuous data, intervals like 10 ≤ t < 15 are used. Remember to use inequality signs correctly.

计数完成后，结果会显示在频数表中。该表格列出每个类别及其对应频数。在处理连续数据的分组频数表时，会用到如 10 ≤ t < 15 的区间。请记住正确使用不等式符号。

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6. Measures of Central Tendency: Mean, Median, Mode | 集中趋势度量：平均数、中位数、众数

The mean is the arithmetic average. To find it, add up all the values and divide by the number of values. Formula: Mean = (sum of data values) ÷ (number of values). It is sensitive to extreme values (outliers). For example, the mean of 2, 3, 3, 4, 8 is (2+3+3+4+8) ÷ 5 = 4.

平均数是算术平均值。求法是将所有数值相加，再除以数值的个数。公式：平均数 = (数据值总和) ÷ (数值个数)。它对极端值（离群值）很敏感。例如，2, 3, 3, 4, 8 的平均数是 (2+3+3+4+8) ÷ 5 = 4。

The median is the middle value when the data are arranged in order. If there is an even number of data, the median is the mean of the two middle numbers. The median is unaffected by outliers, which makes it useful for data like house prices. In the set 2, 3, 3, 4, 8, the median is 3.

中位数是将数据排序后处于中间位置的值。如果数据个数是偶数，则中位数是中间两个数的平均数。中位数不受离群值影响，因此在房价等数据中很实用。在集合 2, 3, 3, 4, 8 中，中位数是 3。

The mode is the value that appears most often. A set of data can have one mode (unimodal), more than one mode (bimodal or multimodal), or no mode if all values are different. The mode is the only average suitable for categorical data — you cannot calculate a mean or median favourite colour.

众数是出现次数最多的值。一组数据可以有一个众数（单峰），多个众数（双峰或多峰），或没有众数（如果所有值都不同）。众数是唯一适用于分类数据的平均数 —— 你无法计算最喜欢的颜色的平均数或中位数。

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7. Range and Spread | 极差与离散程度

The range measures how spread out the data are. It is calculated by subtracting the smallest value from the largest value: Range = maximum − minimum. A larger range suggests more variability. For instance, if the highest temperature is 22°C and the lowest is 8°C, the range is 14°C.

极差衡量数据的离散程度。计算方法是用最大值减去最小值：极差 = 最大值 − 最小值。极差越大，说明变异性越大。例如，最高温度 22°C，最低温度 8°C，则极差是 14°C。

Although range is quick to calculate, it only considers the two extremes. In KS3, you are not required to use interquartile range, but you should know that a single unusual value can make the range very large. Always compare the range alongside a measure of centre, like the median.

尽管极差计算简单，但它只考虑了两个极端值。在 KS3 阶段，你不需要使用四分位距，但你应该知道，一个异常值就能让极差变得很大。始终将极差与某个集中趋势度量（如中位数）一起比较。

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8. Data Visualization: Charts and Graphs | 数据可视化：图表

A bar chart represents categorical data with rectangular bars. The height (or length for horizontal bars) shows the frequency or value. The bars are separated by gaps because the categories are distinct. A bar line chart uses thin lines instead of wide bars, often for discrete numerical data.

条形图用长方形条表示分类数据。条的高度（或水平条的长度）表示频数或数值。由于类别互不连续，条与条之间留有空隙。条形折线图用细线代替宽条，常用于离散数值数据。

A pie chart is a circle divided into sectors. Each sector angle is proportional to the frequency it represents. To draw a pie chart, calculate the angle using: (frequency ÷ total frequency) × 360°. Pie charts are best for showing proportions of a whole, but avoid too many categories.

饼图是一个划分为扇形的圆。每个扇形的角度与其表示的频数成正比。绘制饼图时，用 (频数 ÷ 总频数) × 360° 计算角度。饼图最适合展示各部分占整体的比例，但要避免过多类别。

A line graph uses points connected by straight lines, typically for data collected over time. It is excellent for showing trends and changes. For example, a line graph can display temperature changes over a week. A pictogram uses small icons to represent data; a key tells you how many items each icon stands for.

折线图用点及连接各点的直线表示数据，通常用于随时间收集的数据。它非常适合展示趋势和变化。例如，折线图可以显示一周的温度变化。象形图用小图标表示数据；图例会告诉你每个图标代表多少个单位。

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9. Interpreting Graphs | 解读图表

Reading a graph means more than identifying the tallest bar. You must identify trends (‘increasing’, ‘decreasing’, ‘steady’) and make comparisons. Look at the axes labels to know what is being measured and check the scale. Misleading graphs can use a broken scale or unequal intervals to exaggerate differences.

阅读图表不仅仅是找出最高的柱形。你必须识别趋势（‘上升’、‘下降’、‘平稳’）并做出比较。观察坐标轴标签以了解测量对象，并检查刻度。误导性图表可能使用截断的刻度或不等的间隔来夸大差异。

A scatter graph (or scatter plot) shows the relationship between two numerical variables. Each point represents a pair of values. If the points go uphill from left to right, there is a positive correlation; if they go downhill, a negative correlation; if no pattern, no correlation. Correlation does not imply causation.

散点图（或散点图）显示两个数值变量之间的关系。每个点代表一对值。如果点从左到右呈上升趋势，则为正相关；如果呈下降趋势，则为负相关；如果没有规律，则为无相关。相关关系不等于因果关系。

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10. Introduction to Probability | 概率入门

Probability measures how likely an event is to happen. It is expressed as a number between 0 and 1, or as a fraction, decimal or percentage. A probability of 0 means impossible; a probability of 1 means certain. The probability scale helps you visualise likelihoods: ‘even chance’ is 0.5.

概率衡量一个事件发生的可能性大小。它用 0 到 1 之间的数字表示，也可用分数、小数或百分比。概率为 0 表示不可能；概率为 1 表示必然。概率尺度帮助你直观理解可能性：‘相等机会’是 0.5。

The probability of an event A is written as P(A). If all outcomes are equally likely, P(A) = (number of outcomes in A) ÷ (total number of outcomes). You must ensure the coin, die or spinner is fair (unbiased) for this to hold. If biased, the probabilities will not be equal.

事件 A 的概率记作 P(A)。如果所有结果等可能，则 P(A) = (事件 A 包含的结果数) ÷ (总结果数)。你必须确保硬币、骰子或转盘是公平的（无偏倚）才能使用此公式。若有偏倚，概率将不相等。

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11. Key Probability Terms | 核心概率术语

An experiment is a repeatable process that produces outcomes, such as rolling a die. The sample space is the set of all possible outcomes, often listed inside curly braces { }. An event is a specific outcome or a set of outcomes that you are interested in, like ‘rolling a prime number’.

试验是一个可重复的过程，会产生结果，如掷骰子。样本空间是所有可能结果的集合，通常用花括号 { } 列出。事件是你感兴趣的某个特定结果或一组结果，如‘掷出质数’。

Two events are mutually exclusive if they cannot happen at the same time. For example, getting heads and tails on a single coin flip are mutually exclusive. The probability of either happening is P(A) + P(B). Exhaustive events cover all possible outcomes, so their probabilities sum to 1.

如果两个事件不能同时发生，则它们是互斥事件。例如，掷一枚硬币得到正面和反面是互斥的。两者中任一发生的概率是 P(A) + P(B)。穷举事件覆盖所有可能结果，因此它们的概率之和为 1。

Expected frequency predicts how many times an event will occur in repeated trials: Expected frequency = probability × number of trials. In KS3, this is used to check if an observed frequency seems fair or biased.

期望频数预测在多次试验中事件会发生的次数：期望频数 = 概率 × 试验次数。在 KS3 中，用它来检验观察到的频数是否像公平结果或存在偏倚。

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12. Summary and Memorization Tips | 总结与记忆技巧

Create flashcards with the term on one side and the definition plus a Chinese prompt on the other. Group related terms: for example, mean, median, mode and range form the ‘averages and spread’ family. Draw your own diagrams to label parts like the frequency axis, sectors and scatter points.

制作抽认卡，一面写术语，另一面写定义和中文提示。将相关术语分组：例如平均数、中位数、众数和极差构成‘平均与离散’家族。自己画图并为坐标轴、扇区和散点等部分标注。

Use mnemonics: ‘CATegorical data is about CATegories’ helps remind you it is qualitative. Remember that mean is the ‘mean one’ affected by outliers, while median stands in the middle. Practice by collecting simple data at home — tally the colours of socks in a drawer or measure the lengths of leaves — and calculate all statistics.

使用记忆术：‘CATegorical data 是关于 CATegories（类别）的’可以帮助你记住它是定性数据。记住平均数（mean）受离群值影响较大，而中位数（median）站在中间。在家收集简单数据做练习——统计抽屉里袜子的颜色或测量叶子的长度——然后计算所有统计量。

Finally, always read questions carefully to identify whether data is categorical or numerical, discrete or continuous, because this determines the appropriate charts and measures. With these terms firmly in your memory, KS3 statistics becomes a logical puzzle rather than a guessing game.

最后，始终仔细读题，辨认数据是分类还是数值，是离散还是连续，因为这决定了适合的图表和度量。当这些术语牢牢扎根于你的记忆中，KS3 统计就不再是猜谜游戏，而是一道道逻辑谜题。

Published by TutorHao | Statistics Revision Series | aleveler.com

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