📚 Year 8 WJEC Statistics: Vocabulary & Terminology Quick Revision Guide | Year 8 WJEC 统计：词汇术语速记指南
Welcome to your fast-track revision resource for Year 8 WJEC Statistics. Getting comfortable with the language of data is half the battle – once you know what words like ‘discrete’, ‘median’ or ‘correlation’ really mean, the number work becomes much clearer. This guide groups the must-know terms into logical topics, giving you a bilingual memory boost for every concept.
欢迎使用 Year 8 WJEC 统计快速复习资源。熟悉数据的语言已经成功了一半—— 一旦你真正理解“离散”、“中位数”或“相关性”这些词的含义，数字运算会变得清晰很多。本指南把必知术语按逻辑主题分组，为每个概念提供双语记忆强化。
1. Data Types | 数据类型
Data is simply information. In statistics, we split data into qualitative (descriptions, like eye colour) and quantitative (numbers, like test scores). Quantitative data can be discrete – things we count in whole numbers, such as the number of pets – or continuous, which can take any value on a measurement scale, like height or time.
数据就是信息。在统计中，我们把数据分为定性数据（描述，如眼睛颜色）和定量数据（数字，如测验分数）。定量数据可以是离散的——用整数来计数的东西，比如宠物数量——也可以是连续的，可以在测量尺度上取任何值，比如身高或时间。
| English Term | 中文术语 | Quick definition |
|---|---|---|
| Qualitative | 定性 | Describes qualities or categories |
| Quantitative | 定量 | Numerical data |
| Discrete | 离散 | Can only take specific values (often counts) |
| Continuous | 连续 | Can take any value within a range |
Remember: discrete data jumps between values (you can’t have 2.3 students), while continuous data flows smoothly (a runner’s time can be 10.55 seconds). This difference affects which graphs and averages you use.
请记住：离散数据在数值间跳跃（你不会说 2.3 个学生），而连续数据是平滑流动的（跑步成绩可以是 10.55 秒）。这一区别会影响你使用的图表和平均数类型。
2. Measures of Central Tendency | 集中趋势度量
These measures describe the centre of a data set. The mean is the sum of all values divided by the number of values. The median is the middle number when the data is ordered from smallest to largest. The mode is the value that appears most often, and a set can have more than one mode, or no mode at all.
这些度量用于描述数据集的中心。 平均数是所有数值之和除以数值个数。中位数是将数据从小到大排序后位于中间的那个数。众数是出现次数最多的数值，一组数据可以有一个以上的众数，也可以没有众数。
A quick memory trick: ‘Mean’ sounds like ‘mean’ to calculate – you have to do the most maths. ‘Median’ reminds you of ‘medium’ or middle. ‘Mode’ starts with the same letters as ‘most’. If these three give quite different numbers, your data might be skewed by outliers.
快速记忆窍门：’Mean’（平均数）听上去就很“麻烦”——需要做最多的计算。’Median’（中位数）会让你联想到 ‘medium’ 或中间。’Mode’（众数）的开头字母和 ‘most’ 一样。如果这三个数给出差别很大的结果，你的数据可能被异常值扭曲了。
3. Measures of Spread | 离散程度
Spread tells you how spread out the data is. The simplest measure is the range: largest value – smallest value. Later you will meet the interquartile range (IQR), which focuses on the middle 50% of data and is less affected by extremes.
离散程度告诉你数据有多分散。最简单的度量是极差：最大值 – 最小值。以后你会学到四分位距 (IQR)，它关注中间 50% 的数据，受极端值影响较小。
When a range is small, the values are bunched closely together. A large range means the data is very spread out. Always write the range with units, for example ‘the range of heights is 42 cm’.
当极差很小时，数值紧密地聚在一起。较大的极差意味着数据非常分散。写极差时一定要带上单位，比如“身高的极差是 42 cm”。
4. Data Collection | 数据收集
Knowing where data comes from helps you judge its reliability. Primary data is collected by you, for your own research – a survey you design is a good example. Secondary data is collected by someone else, such as information from a newspaper, database or previous study.
知道数据的来源有助于你判断其可靠性。一手数据是你为了自己的研究而搜集的——你自己设计的调查就是一个好例子。二手数据是由他人搜集的，例如来自报纸、数据库或以往研究的信息。
When you ask questions, avoid leading questions that push people towards a particular answer. A sample is a smaller group selected from a population, which is the whole group you want to know about. A census collects data from every single member of the population. A sample must be unbiased if it is to represent the population well.
设计问题时，要避免诱导性问题，即把人们推向某个特定答案的问题。样本是从总体（你想了解的全部对象）中选出的较小群体。 普查则收集总体中每一个成员的数据。样本若要有良好的代表性，就必须是无偏的。
5. Organising Data | 数据整理
Once data is collected, it needs sorting. A tally chart uses strokes to count frequencies – every fifth stroke crosses the previous four, making groups of five easy to see. Frequency simply means how many times something occurs.
收集好数据后，需要整理。频数划记表利用划痕来计数——每第五划将前四划斜穿，方便快速看到五个一组。频数就是指某事物出现的次数。
For continuous data, we often group values into class intervals, such as 150 cm ≤ h < 160 cm. The notation shows that 150 is included, but 160 is not. Grouping makes patterns easier to spot, even though we lose some detail.
对于连续数据，我们经常将数值分组为组距，例如 150 cm ≤ h < 160 cm。这种符号表示 150 包括在内，而 160 不包括。分组后更容易看出规律，尽管会丢失一些细节。
6. Charts and Graphs | 图表
Different charts suit different data types. A bar chart has gaps between bars and is used for qualitative or discrete categories. A pictogram uses symbols to represent frequencies – always include a key to show what one symbol stands for. A pie chart shows proportions: the total must add up to 100% or 360°.
不同的图表适合不同的数据类型。条形图的条形之间有间隙，用于定性或离散类别。象形图用符号代表频数——别忘了附上图例显示每个符号代表多少。饼状图展示比例：总和必须等于 100% 或 360°。
When looking at trends over time, use a line graph. For examining relationships between two continuous variables, a scatter graph is best. Every good graph needs clear labels, a title, and sensibly scaled axes. The horizontal axis is often called the x‑axis, and the vertical is the y‑axis.
观察随时间变化的趋势时，应使用折线图。若要分析两个连续变量之间的关系，最好用散点图。每一幅规范的图表都需要清晰的标签、标题以及刻度合理的坐标轴。横轴通常称为 x 轴，竖轴称为 y 轴。
7. Working with Frequency Tables | 频数表的使用
A frequency table organises raw data so you can find averages more easily. The modal class is the group with the highest frequency – important when data is grouped. You can work out the mean from a frequency table by adding a column for ‘value × frequency’, finding the total, and dividing by the total frequency.
频数表将原始数据整理好，以便你更容易找到平均数。众数组是频数最高的那个组——这在数据被分组时很重要。你可以通过添加一列“数值 × 频数”求出总数，再除以总频数，从频数表计算出平均数。
In Year 8, you will mainly meet ungrouped frequency tables. The median can be found by working out the position: (total frequency + 1) ÷ 2, then counting through the data until you reach that position.
在 Year 8，你主要会接触到未分组的频数表。中位数可以通过确定位置来寻找：(总频数 + 1) ÷ 2，然后顺着数据往下数，直到抵达那个位置。
8. Probability Vocabulary | 概率术语
Probability is the language of chance. An experiment is any process that produces observable results; a single result is an outcome. An event is a set of outcomes. When all outcomes have the same chance, we call them equally likely.
概率是描述机会的语言。试验是产生可观察结果的任何过程；单个结果称为结果。事件是一组结果的集合。当所有结果的机会相同时，我们称它们为等可能。
The probability scale runs from 0 (impossible) to 1 (certain). Probabilities can be written as fractions, decimals or percentages. The probability of an event not happening is 1 – probability that it does happen.
概率标尺从 0（不可能）到 1（必然）。概率可以写成分数、小数或百分数。某事件不发生的概率等于 1 减去该事件发生的概率。
9. Correlation and Relationships | 相关性与关系
When you plot two sets of data on a scatter graph, you might see a pattern called correlation. Positive correlation means as one variable increases, the other also tends to increase – for example, study hours and marks. Negative correlation means one variable goes up while the other goes down – like a car’s age and its value.
当你把两组数据画在散点图上时，可能会看到一种叫做相关性的模式。正相关意味着当一个变量增加时，另一个也趋向增加——例如学习时间和分数。负相关指一个变量上升时另一个反而下降——比如车龄和车价。
If the points look like a random cloud, there is no correlation. When a pattern exists, you can draw a line of best fit through the middle of the points to show the trend and make predictions. Remember: correlation does not mean one thing causes the other.
如果点看上去像随机云团，那就是没有相关性。当模式存在时，你可以穿过点群中间画一条最佳拟合线来展示趋势并进行预测。记住：相关不意味着因果关系。
10. Memory Aids and Common Pitfalls | 速记技巧与常见误区
Use a rhyme to lock in the three averages: “Hey diddle diddle, the median’s the middle; you add and divide for the mean; the mode is the one you’ve seen the most.” Stick this on a sticky note!
用一首押韵短诗记住三个平均数：“Hey diddle diddle, the median’s the middle; you add and divide for the mean; the mode is the one you’ve seen the most.” 把它贴在便利贴上吧！
Avoid classic mistakes: confusing the x‑axis with the y‑axis, forgetting to order the data before finding the median, and labelling a pie chart with frequencies instead of percentages or angles. Also, never assume correlation means causation – this catches many out.
要避免的经典错误：把 x 轴与 y 轴搞混，在找出中位数前忘记将数据排序，以及在饼状图上标注频数而不是百分数或角度。同样，绝不要假设相关性意味着因果关系——这点经常让人中招。
Finally, make your own bilingual glossary cards. Write the English term on one side and the Chinese explanation on the other. Test yourself when you have a spare five minutes – active recall is your strongest revision weapon.
最后，制作自己的双面词汇卡片。一面写英文术语，另一面写中文解释。利用碎片时间自测——主动回忆是你最强大的复习工具。
Published by TutorHao | Statistics Revision Series | aleveler.com
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