IGCSE Edexcel Psychology: Experiments and Practical Assessment Guide | IGCSE Edexcel 心理学：实验/实践考核要点

📚 IGCSE Edexcel Psychology: Experiments and Practical Assessment Guide | IGCSE Edexcel 心理学：实验/实践考核要点

In IGCSE Edexcel Psychology, understanding experimental methods and practical assessment criteria is essential for success in both the written examination and the practical components. This guide covers the key points you need to master, from formulating hypotheses to ethical practice and evaluating findings.

在 IGCSE Edexcel 心理学中，理解实验方法和实践考核标准对于笔试与实践环节的成功至关重要。本指南涵盖你需要掌握的关键要点，从提出假设到伦理实践和评估结果。

1. The Experimental Method | 实验方法

The experimental method involves manipulating one variable (the independent variable, IV) to observe the effect on another variable (the dependent variable, DV) while controlling extraneous variables. This allows researchers to establish cause-and-effect relationships.

实验方法涉及操控一个变量（自变量，IV），以观察其对另一个变量（因变量，DV）的影响，同时控制外来变量。这使研究者能够建立因果关系。

Experiments can be conducted in a laboratory, field, or online setting. In IGCSE Psychology, you will often design and evaluate both lab and field experiments.

实验可在实验室、现场或在线环境中进行。在 IGCSE 心理学中，你通常会设计和评估实验室实验和现场实验。

2. Aims and Hypotheses | 研究目的与假设

Every study begins with an aim – a general statement of what the researcher intends to investigate. From the aim, a hypothesis is generated: a precise, testable prediction about the relationship between variables.

每项研究都始于一个目的——对研究者打算调查的内容的一般性陈述。基于目的，产生假设：一个关于变量关系的精确、可检验的预测。

There are two types: a directional (one-tailed) hypothesis, which predicts the direction of the effect (e.g., ‘Participants who drink caffeine will have faster reaction times than those who drink water’), and a non-directional (two-tailed) hypothesis, which simply states there will be a difference without specifying direction (e.g., ‘There will be a difference in reaction times between participants who drink caffeine and those who drink water’).

假设有两种类型：方向性（单尾）假设，预测效应的方向（例如，”饮用咖啡因的参与者反应时间比饮用水的参与者快”），和非方向性（双尾）假设，仅说明存在差异但不指定方向（例如，”饮用咖啡因的参与者和饮用水的参与者在反应时间上存在差异”）。

Both null and alternative hypotheses are considered. The null hypothesis (H0) states there is no significant difference or relationship, while the alternative (experimental) hypothesis (H1) is what you actually test.

同时考虑零假设和备择假设。零假设 (H0) 陈述没有显著差异或关系，而备择（实验）假设 (H1) 是你实际检验的假设。

3. IV, DV and Operationalisation | 自变量、因变量与操作化

The independent variable (IV) is the factor manipulated by the researcher. The dependent variable (DV) is the factor measured. Both must be operationalised – defined clearly in terms of the procedures used to manipulate or measure them. For example, instead of saying ‘memory’, operationalise it as ‘number of words recalled from a list of 20’.

自变量 (IV) 是由研究者操控的因素。因变量 (DV) 是被测量的因素。两者都必须操作化——根据用于操控或测量它们的程序明确定义。例如，不要说”记忆力”，而应操作为”从包含 20 个单词的列表中回忆出的单词数”。

Operationalisation is crucial for replication and objectivity. In the exam, you may be asked to suggest how a variable could be operationalised or to critique the operationalisation used in a scenario. When writing an operationalised hypothesis, you must describe exactly how you will measure the DV, e.g., ‘The number of words correctly recalled from a list of 20 words after a delay of 5 minutes.’

操作化对于可重复性和客观性至关重要。在考试中，你可能会被要求建议如何操作化一个变量，或批判某个场景中使用的操作化。在撰写操作化假设时，你必须准确描述如何测量 DV，例如，”在延迟 5 分钟后，从 20 个单词列表中正确回忆出的单词数量”。

4. Experimental Designs | 实验设计

Choosing the right experimental design is a fundamental skill. The three main designs are: Independent Groups Design, Repeated Measures Design, and Matched Pairs Design.

选择合适的实验设计是一项基本技能。三种主要设计是：独立组设计、重复测量设计和配对组设计。

The table below summarises their key features, strengths, and weaknesses.

下表总结了它们的主要特征、优点和缺点。