📚 Year 7 WJEC Statistics: Key Points for Experimental and Practical Assessments | Year 7 WJEC 统计：实验与实践考核要点
Practical assessments in Year 7 WJEC Statistics let you become a real data detective. You will be asked to plan a simple investigation, collect information, organise it, and explain what the numbers tell you.
在 Year 7 WJEC 统计的实践考核中，你将化身为一名真正的数据侦探。你需要设计一个小型调查，收集信息，整理数据，并解释这些数字说明了什么。
These tasks are not about memorising facts; they are about using the statistical cycle correctly. You will be assessed on how you ask a question, gather data fairly, choose the right diagrams, and write a short conclusion.
这些任务并不是死记硬背，而是要求你正确运用统计周期。考评将关注你如何提出问题、公平地收集数据、选择合适的图表，以及撰写简短的结论。
1. Understanding the Nature of Practical Tasks | 理解实践任务的性质
In Year 7, a practical statistics task usually revolves around a survey or an experiment you can carry out in your school or at home. The goal is to follow each step of the statistical cycle carefully.
在 Year 7，统计实践任务通常围绕一项你可以在学校或家中完成的小调查或小实验。目标是仔细地依循统计周期的每一个步骤。
Your teacher will look for evidence of planning, clear data recording, sensible charts, and a conclusion that links back to your original question. Neat presentation and logical thinking are just as important as the numbers themselves.
你的老师会寻找以下证据：计划过程、清晰的数据记录、合理的图表，以及能回扣原问题的结论。整洁的表达和条理清晰的思维与数字本身同样重要。
Remember, you are not expected to find a ‘right answer’. The focus is on the process: how you collect data, how you handle it, and how you explain patterns or surprises.
请记住，你并不需要找到一个“正确答案”。重点在于过程：你如何收集数据、如何处理数据，以及你如何解释其中的规律或意想不到的结果。
2. Starting with a Good Statistical Question | 从一个好的统计问题开始
Every investigation begins with a clear statistical question. A good question is one that can be answered by collecting data that varies, such as ‘How many hours do Year 7 pupils spend on homework each week?’ or ‘What is the most common lunch choice in our canteen?’
每项调查都从一个明确的统计问题开始。一个好问题应该是能够通过收集具有变异性的数据来回答的，比如“Year 7 学生每周花多少小时做作业？”或“我们食堂最受欢迎的午餐选择是什么？”。
Avoid questions that have a single fixed answer or are too vague. For example, ‘How tall am I?’ is not a statistical question because it only asks about one person, and there is no variation to investigate.
避免提出只有一个固定答案或过于模糊的问题。例如，“我有多高？”就不是一个统计问题，因为它只针对一个人，没有任何可供研究的变异性。
Always frame your question so that you are comparing groups, looking for a trend, or summarising a wide range of answers. Write down your question exactly as you plan to investigate it.
记得把问题设定为比较不同组别、寻找趋势或概括一系列回答。把你打算研究的准确问题写下来。
3. Designing the Data Collection Method | 设计数据收集方法
Once you have a question, decide how you will collect the data. For a survey, you might use a questionnaire with simple tick‑boxes. For an experiment, you could measure something like the stretch of a rubber band or the time taken to run 50 metres.
有了问题之后，就要决定如何收集数据。如果是问卷调查，你可以设计一份带有简单勾选框的问卷。如果是实验，你可以测量橡皮筋的拉伸长度，或跑 50 米所需的时间。
Think carefully about what you will record. If you are asking about favourite sports, list a few common options but always include an ‘other’ choice so nobody is left out. If you are measuring length, decide whether to use centimetres or millimetres.
仔细想想你要记录什么。如果你调查最喜欢的运动，列出几个常见选项，但务必加上“其他”选项，避免有人无法选择。如果你测量长度，要事先决定使用厘米还是毫米。
It is also important to plan who you will ask or what you will test. Will you survey everyone in your class, or will you pick a sample? Make sure your sample is large enough to show patterns, but not so large that you cannot handle the data.
同样重要的是，计划好你的调查对象或测试对象。你打算调查全班同学还是抽取一个样本？要确保样本足够大，能显现出规律，但也不至于大到让你无法处理数据。
4. Creating Effective Data Recording Sheets | 制作有效的数据记录表
Before you gather any numbers, design a tally chart or data table. A well‑organised table stops you from getting confused later and makes it much easier to count frequencies.
在开始收集任何数据之前，先设计一个计数图表或数据表。一个条理清晰的表格可以避免你事后手忙脚乱，并且能让你更容易数出频数。
A simple tally chart has three columns: one for the category or result, one for the tally marks, and one for the final frequency. Use the ‘five‑bar gate’ method (four vertical strokes and a diagonal stroke for the fifth) to group counts quickly.
一个简单的计数图表通常包含三列：一列是类别或结果，一列是计数记号，另一列是最终频数。使用“正字计数法”（画四竖一横代表五）可以让你迅速将数目分组。
Here is an example of what your recording sheet might look like when gathering data on favourite fruits:
下面是一个你在收集“最喜欢的水果”数据时可能用到的记录表示例：
| Fruit | Tally | Frequency |
|---|---|---|
| Apple | IIII | 4 |
| Banana | IIII I | 6 |
| Orange | III | 3 |
| Other | II | 2 |
5. Collecting Data in a Fair Way | 公平地收集数据
When you carry out your investigation, it is vital to be fair and unbiased. Do not guide people towards a certain answer, and do not change your measurements to fit what you expect.
在进行调查时，保持公平、避免偏见至关重要。不要引导别人给出某种特定答案，也不要为了迎合预期而篡改测量数据。
If you are asking questions, use the same wording for everyone. For timed experiments, start the stopwatch at the same moment and use the same measuring instrument each time to keep results consistent.
如果你在提问，要对每个人都使用相同的措辞。在计时实验中，要在同一时刻启动秒表，并且每次使用相同的测量工具，以保证结果的一致性。
Record the data exactly as it appears, even if a result looks odd. An unusual response might be a genuine mistake, but it could also be an interesting piece of evidence. Never ignore a value just because you do not like it.
如实地记录数据，哪怕某个结果看起来很奇怪。异常的回答可能确实是错误，但也可能是一份有趣的证据。千万不要因为你不喜欢某个数值就忽略它。
6. Sorting and Presenting Raw Data | 整理与展示原始数据
After you have collected all your data, the next step is to organise it into a frequency table. Group the raw numbers or categories and count how many times each one appears.
收集完所有数据后，下一步是将它整理成一个频数表。把原始数据或类别分组，然后数出每一类出现的次数。
If you have a lot of different numerical values, you may need to group them into equal‑sized intervals, such as 0‑4, 5‑9, 10‑14, and so on. This makes patterns easier to spot and prepares your data for drawing a chart.
如果你有许多不同的数值，可能需要将它们分成大小相等的区间，比如 0–4、5–9、10–14 等等。这样做更容易发现规律，也为绘制图表做好了准备。
Always include a total row so you can check that you have not lost any data. A clear frequency table is the foundation of almost every good graph or statistical calculation you will perform next.
务必在表格中包含总计行，这样你就能核对是否有数据丢失。一个清晰的频数表是你接下来绘制任何优质图表或进行统计计算的基础。
7. Creating Bar Charts and Pictograms | 绘制条形图和象形图
For categorical data, a bar chart is often the best choice. Remember to label both axes, give the chart a title, and keep the bars separate to show that the categories are distinct.
对于分类数据，条形图往往是最佳选择。请记得给两个坐标轴标注，给图表加上标题，并让条形之间保持间隔，以显示各个类别是互相独立的。
A pictogram uses simple symbols to represent a certain number of items, for example one smiley face could stand for two pupils. You must include a key that explains what your symbol means, and make sure all symbols are the same size.
象形图用一个简单的符号表示一定数量的项目，比如一个笑脸可以代表两名学生。你必须附带一个图例来说明符号的含义，并确保所有符号的大小一致。
Whichever graph you choose, the goal is to make the data easier to understand at a glance. A messy or unlabelled chart does not help your reader and may lose you marks in a practical assessment.
无论你选择哪种图表，目标都是让人一眼就能看懂数据。杂乱无章或没有标注的图表对你的读者毫无帮助，还可能在实践考核中被扣分。
8. Calculating Averages and the Range | 计算平均数与范围
In Year 7, you are likely to work with three types of average: the mode (the most common value), the median (the middle value when ordered), and the mean (the total shared out equally).
在 Year 7，你通常会接触到三种平均数：众数（最常见的值）、中位数（按顺序排列后的中间值）和平均数（总数平均分配后得到的值）。
To find the mean, add up all the numbers and divide by how many numbers you have. This single value gives you a sense of a ‘typical’ result.
要计算平均数，先把所有数值相加，再除以数值的总个数。这个单一数值能让你了解“典型”结果的大致水平。
Mean = Sum of all values ÷ Number of values
计算方法为：平均数 = 所有数值之和 ÷ 数值的个数。
The range tells you how spread out the data is. Subtract the smallest value from the largest value. A small range means the data is clustered close together; a large range shows a wide variation.
极差则告诉你数据分布的广度。用最大值减去最小值即可。极差小意味着数据比较集中；极差大则表明数据有很大的差异性。
9. Writing a Simple Report of Findings | 撰写简单的调查发现报告
A practical task almost always ends with a short written summary. Start by restating your original question, then describe what your data shows in a few clear sentences.
实践任务几乎总是以一份简短的书面总结收尾。首先重申你最初的问题，然后用几句清晰的话描述你的数据说明了什么。
Refer to your charts and the averages you have calculated. For example, you might write: ‘The bar chart shows that apples were the most popular fruit. The mode was apple, and the range of votes was small, meaning most pupils like similar fruits.’
要引用你的图表和你计算出来的平均数。例如，你可以这样写：“条形图显示苹果是最受欢迎的水果。众数是苹果，且票数的极差很小，这意味着大多数学生喜欢相似的水果。”
Do not just repeat the numbers; try to explain what they might mean. Could there be a reason for a surprising result? Mention any patterns or unusual values and suggest what they might tell you.
不要只是重复数字，而要试着解释这些数字可能意味着什么。某个令人意外的结果是否有原因？请提到任何规律或异常值，并说明它们可能给你的启示。
10. Checking Your Work and Making Improvements | 检查你的工作并作出改进
Before you hand in your investigation, go back through every stage. Check your tally marks against your raw data, make sure your frequency totals are correct, and read your graph labels aloud.
在提交你的调查作业之前，请把每一个步骤都回顾一遍。对照原始数据检查计数记号，确保频数总计正确无误，并把图表标签大声读一遍。
Think about what you could do differently next time. Maybe you could ask more people, use a different measuring tool, or choose a clearer way of grouping data. Evaluations like this show real statistical thinking.
想一想下一次你可以有什么不同的做法。也许可以调查更多的人，使用不同的测量工具，或者选择一种更清晰的数据分组方式。这样的评估能体现出真正的统计思维。
Even small improvements, such as adding a unit to an axis or spacing your bars evenly, can turn a good investigation into an excellent one. In practical assessments, the ability to spot your own mistakes and suggest fixes is often what earns the highest grades.
即使是很小的改进，例如在坐标轴上添加单位或让条形保持均匀间距，也能把一个好的调查变得更出色。在实践考核中，能够发现自己错误并提出改进方案往往是获得高分的关键。
Published by TutorHao | Statistics Revision Series | aleveler.com
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