📚 Year 7 CIE Science: Case Study Practical Exercise | Year 7 CIE 科学：案例分析实战演练
Case studies are an essential part of your CIE Year 7 science course. They give you the chance to apply scientific skills to real situations, from analysing data to drawing conclusions. By working through case study examples, you learn how to think like a scientist, evaluate evidence and write clear explanations.
案例分析是 Year 7 CIE 科学课程的重要组成部分。它们让你有机会将科学技能应用到真实情境中，从分析数据到得出结论。通过练习案例分析，你将学会像科学家一样思考，评估证据，并写出清晰的解释。
1. What Is a Case Study in Science? | 科学中的案例研究是什么？
A case study in science is a detailed investigation of a specific experiment or scenario. It often provides you with background information, a set of results and sometimes a graph. Your task is to examine the data, identify patterns and answer questions using scientific knowledge.
科学中的案例研究是对特定实验或情景的详细调查。它通常会提供背景信息、一系列结果，有时还有图表。你的任务是检查数据，识别规律，并运用科学知识回答问题。
For Year 7, case studies typically focus on simple fair tests. You might be asked to name the independent variable, suggest improvements or explain what the results show. The key is to practise reading information carefully and thinking logically.
在 Year 7，案例研究通常集中在简单的公平实验上。你可能会被要求指出自变量，提出改进建议，或解释结果说明了什么。关键是要练习仔细阅读信息并进行逻辑思考。
2. Our Sample Case: Light and Seedling Growth | 我们的案例：光照与幼苗生长
Let's work through a typical Year 7 case study. A student wanted to find out how light affects the growth of mung bean seedlings. She planted 30 seeds in identical pots of soil. Ten pots were placed in full sunlight, ten in half light (covered with thin cloth), and ten in a dark cupboard. All pots received the same amount of water and were kept at room temperature (20 °C). After 7 days, she measured the height of each seedling in centimetres.
我们来完成一个典型的 Year 7 案例。一位学生想研究光照如何影响绿豆幼苗的生长。她把 30 颗种子种在相同的花盆里。10 盆放在全日照下，10 盆放在半光照下（用薄布遮盖），10 盆放在黑暗橱柜里。所有花盆浇等量的水，并保持在室温（20 °C）。7 天后，她测量了每株幼苗的高度，单位是厘米。
The results will be shown in later sections. This case will help us practise key skills such as identifying variables, constructing tables, plotting graphs and drawing conclusions.
结果将在后面的部分展示。这个案例可以帮助我们练习关键技能，如识别变量、构建表格、绘制图表和得出结论。
3. Identifying the Key Variables | 识别关键变量
In any experiment, there are three types of variables. The independent variable is what you change. The dependent variable is what you measure. The control variables are what you keep the same. For the seedling experiment:
在任何实验中，都有三种类型的变量。自变量是你改变的量。因变量是你测量的量。控制变量是你保持不变的量。对于幼苗实验：
Independent variable: amount of light (full light, half light, no light)
自变量：光照量（全光照、半光照、无光照）
Dependent variable: height of seedlings (in cm) after 7 days
因变量：7 天后幼苗的高度（单位：厘米）
Control variables: type of seed, amount of water, size of pot, type of soil, temperature
控制变量：种子类型、浇水量、花盆大小、土壤类型、温度
When you identify these in a case study question, always think about what was changed, what was measured and what stayed the same. This shows you understand the scientific method.
当你在案例分析问题中识别这些变量时，始终思考什么被改变了，什么被测量了，什么保持不变。这表明你理解了科学方法。
4. Designing a Fair Test | 设计公平实验
A fair test means only the independent variable is changed; all other conditions are controlled. The seedling experiment is fair because the student used the same type of seed, pot size, amount of water and temperature. If she had given more water to the plants in full light, then the test would not be fair – we could not be sure if the height difference was due to light or water.
公平实验意味着只改变自变量；所有其他条件都受到控制。幼苗实验是公平的，因为学生使用了相同类型的种子、花盆大小、浇水量和温度。如果她给全光照下的植物多浇水，那么实验就不公平了——我们无法确定高度差异是由于光照还是水分造成的。
In a case study, you may be asked to explain why an experiment is fair or to suggest how to make it fairer. Always check for control variables that are not properly controlled.
在案例分析中，你可能会被要求解释为什么一个实验是公平的，或者建议如何使其更公平。一定要检查那些没有被适当控制的控制变量。
5. Collecting and Recording Data | 收集与记录数据
Good scientists record results accurately and clearly. In our case study, the student measured each seedling to the nearest 0.1 cm. She repeated the measurement for 10 seedlings in each condition. Repeating measurements makes the data more reliable; we can then calculate an average.
好的科学家能够准确清晰地记录结果。在我们的案例中，学生将每株幼苗测量到最接近的 0.1 厘米。她对每种条件下的 10 株幼苗重复了测量。重复测量使数据更可靠；然后我们可以计算平均值。
The raw data for the full light condition could look like this: 8.2, 7.9, 8.5, 8.0, 7.8, 8.4, 7.7, 8.3, 8.1, 7.6 cm. Notice that the values are similar, which suggests the measurements were taken carefully. Any unusually different value (an anomaly) might need to be checked.
全光照条件下的原始数据可能是这样的：8.2, 7.9, 8.5, 8.0, 7.8, 8.4, 7.7, 8.3, 8.1, 7.6 厘米。注意这些数值很接近，这表明测量是仔细进行的。任何异常不同的数值（异常值）可能需要检查。
6. Organising Data into Tables | 将数据整理成表格
When presenting results, a clear table is essential. The table should have a title and headings with units. For our data, we can show the seedling heights and a calculated average for each light condition. A well-drawn table makes it easy to see patterns.
呈现结果时，清晰的表格至关重要。表格应有标题和带单位的表头。对于我们的数据，我们可以展示每种光照条件下的幼苗高度和计算出的平均值。精心绘制的表格便于观察规律。
| Light condition | Seedling heights (cm) | Average height (cm) |
|---|---|---|
| Full light | 8.2, 7.9, 8.5, 8.0, 7.8, 8.4, 7.7, 8.3, 8.1, 7.6 | 8.05 |
| Half light | 6.1, 5.8, 6.3, 5.9, 6.0, 5.7, 6.4, 5.5, 6.2, 5.6 | 5.95 |
| No light | 3.2, 3.5, 2.9, 3.1, 3.0, 3.3, 2.8, 3.4, 2.7, 3.6 | 3.15 |
When drawing a table, always include the units in the heading, not in every cell. In our example, height is in cm, so the heading says 'Seedling heights (cm)'.
绘制表格时，始终在表头中注明单位，而不是在每个单元格中。在我们的示例中，高度以厘米为单位，因此表头写的是 'Seedling heights (cm)'。
<Published by TutorHao | Year 7 Science Revision Series | aleveler.com
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