Year 9 WJEC Statistics: Vocabulary & Terminology Quick Guide | Year 9 WJEC 统计学：词汇术语速记指南

📚 Year 9 WJEC Statistics: Vocabulary & Terminology Quick Guide | Year 9 WJEC 统计学：词汇术语速记指南

Mastering the language of statistics is the first step to success in WJEC Year 9 Statistics. This guide pairs every key term with a quick memory trick and its Chinese translation to help you learn faster and remember longer.

掌握统计学的语言是在 WJEC 九年级统计学中取得成功的第一步。本指南将每个关键术语与快速记忆技巧及其中文翻译配对，帮助你更快学习、更久记忆。

1. Data Types in Statistics | 统计学中的数据类型

Statistical data can be split into two broad types: qualitative (categorical) and quantitative (numerical). Qualitative data describes qualities or categories, like eye colour (blue, brown, green) or types of transport (bus, car, bike). Quantitative data gives numbers that can be measured or counted.

统计数据可以分为两大类：定性（分类）数据和定量（数值）数据。定性数据描述性质或类别，例如眼睛颜色（蓝、棕、绿）或交通方式（公交、汽车、自行车）。定量数据提供可以测量或计数的数字。

Quantitative data is further split into discrete and continuous. Discrete data can only take certain fixed values – often whole numbers from counting, such as the number of students in a class or shoe sizes. Continuous data can take any value within a range and usually comes from measuring, like height, weight, or time.

定量数据又分为离散和连续。离散数据只能取某些固定值——通常是计数的整数，如班级人数或鞋码。连续数据可以在一个范围内取任意值，通常来自测量，如身高、体重或时间。

Quick trick: to decide between discrete and continuous, ask ‘Can it be 3.5?’ If the answer is yes, it’s continuous. For example, number of pets cannot be 3.5, so it’s discrete; weight can be 3.5 kg, so it’s continuous.

快速技巧：要区分离散还是连续，问自己“可以是3.5吗？”如果答案是肯定的，就是连续的。例如，宠物数量不能是3.5，所以是离散的；体重可以是3.5公斤，所以是连续的。

2. Measures of Central Tendency | 集中趋势的度量

The three measures of average are mean, median, and mode. Each one tells you where the ‘centre’ of the data lies, but in a different way. The mean is the arithmetic average, calculated by adding all values and dividing by the number of values. Formula: Mean = sum of all data values ÷ number of values.

三种平均数的度量是平均数、中位数和众数。它们各自以不同方式告诉你数据的“中心”在哪里。平均数是通过将所有数值相加再除以数值个数计算出的算术平均值。公式：平均数 = 所有数据值之和 ÷ 数据个数。

The median is the middle value when data is ordered from smallest to largest. If there is an even number of data items, the median is the mean of the two middle numbers. The mode is the value or category that appears most often. A data set can have one mode, more than one mode (bimodal or multimodal), or no mode at all.

中位数是将数据从小到大排序后的中间值。如果有偶数个数据项，中位数就是中间两个数的平均数。众数是出现次数最多的值或类别。一个数据集可以有一个众数、多个众数（双众数或多众数），或者根本没有众数。

Memory aid: ‘Mean is mean – you have to add and divide!’ and ‘Median is the middle – put in order and pick the one in the centre’. Mode sounds like ‘most’.

记忆助手：“Mean is mean – 你得加完再除！”以及“Median is the middle – 排好顺序挑中间的”。Mode 听起来像“most”。

3. Measures of Spread | 离散程度的度量

Spread tells us how spread out the data is. The most common measure in Year 9 is the range. Range = largest value – smallest value. It gives a quick idea of the variability in a data set but is affected by outliers.

离散程度告诉我们数据有多分散。九年级最常用的度量是极差。极差 = 最大值 – 最小值。它快速给出了数据集的变异程度，但容易受异常值影响。

Another important spread concept is the interquartile range (IQR), which we may meet later. IQR = upper quartile – lower quartile. It measures the spread of the middle 50% of data, ignoring extremes.

另一个重要的离散概念是四分位距 (IQR)，我们稍后会遇到。IQR = 上四分位数 – 下四分位数。它衡量中间50%数据的分散程度，忽略极端值。

Remember: the range is like the wingspan of your data – from the smallest to the largest. Quartiles divide the data into four equal parts, just like cutting a cake into four pieces.

记住：极差就像数据的翼展——从最小到最大。四分位数将数据分成四个相等的部分，就像把蛋糕切成四块。

4. Collecting Data: Primary vs Secondary & Survey Methods | 收集数据：一手与二手及调查方法

Primary data is information you collect yourself for a specific purpose, e.g. conducting a survey in school or running an experiment. It is up-to-date and relevant, but collecting it takes time and effort. Secondary data is information someone else has already collected, such as data from the internet, news reports, or textbooks. It is quick to obtain but may be biased or outdated.

一手数据是你自己为特定目的收集的信息，例如在学校进行调查或进行实验。它是最新且相关的，但收集需要时间和精力。二手数据是他人已收集的信息，比如来自互联网、新闻报道或教科书的数据。获取很快，但可能有偏见或过时。

We often collect data through surveys using questionnaires. Key terms include: population (the whole group we want to study), sample (a smaller group selected from the population), and census (data from every member of the population).

我们经常通过使用问卷进行调查来收集数据。关键术语包括：总体（我们想研究的整个群体）、样本（从总体中选出的一组较小群体）和普查（来自总体每个成员的数据）。

A good questionnaire has unbiased, clear questions with no overlapping response options. Closed questions give set choices, and open questions allow free-text answers. Closed questions are easier to analyse statistically.

一份好的问卷包含无偏见、清晰的问题，选项不重叠。封闭式问题给出固定选项，开放式问题

Published by TutorHao | Year 9 统计 Revision Series | aleveler.com

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