AS Edexcel Psychology: Key Points for Experimental and Practical Assessments | AS Edexcel 心理学：实验与实践考核要点

📚 AS Edexcel Psychology: Key Points for Experimental and Practical Assessments | AS Edexcel 心理学：实验与实践考核要点

The AS Edexcel Psychology specification places a strong emphasis on research methods, and experimental design is at the heart of psychological investigation. Understanding how to plan, conduct, and evaluate experiments is essential not only for exam success but also for developing scientific thinking. This article summarises the key points you need to master for experimental and practical assessments, including design choices, control of variables, ethical issues, and data analysis.

AS Edexcel 心理学大纲高度重视研究方法，而实验设计是心理学探究的核心。了解如何规划、实施和评估实验不仅对考试成功至关重要，也有利于培养科学思维。本文总结了实验与实践考核的关键要点，包括设计选择、变量控制、伦理问题及数据分析。

1. Foundations of the Experimental Method | 实验方法基础

The experimental method involves manipulating one variable (the independent variable, IV) to observe its effect on another variable (the dependent variable, DV), while keeping all other variables constant. This allows researchers to infer cause-and-effect relationships.

实验方法涉及操纵一个变量（自变量，IV）以观察其对另一个变量（因变量，DV）的影响，同时保持其他变量不变。这使研究者能够推断因果关系。

In AS Psychology, you are expected to distinguish between experiments and non-experimental methods such as observations, self-report techniques, and correlations. Only experiments can establish causality because of the deliberate manipulation of the IV.

在AS心理学中，你需要区分实验和观察、自我报告及相关研究等非实验方法。只有实验能确定因果关系，因为它对自变量进行刻意操纵。

Key terms: the IV is what you change or compare; the DV is what you measure; control variables (CVs) are factors you keep the same to prevent them from affecting the DV.

关键术语：自变量是你改变或比较的因素；因变量是你测量的结果；控制变量是为了防止其对因变量产生影响而保持不变的因素。

---

2. Types of Experiments | 实验类型

Laboratory experiments are conducted in a controlled, artificial environment. They have high internal validity and allow precise control, but may lack ecological validity because the setting is unnatural.

实验室实验在受控的人工环境中进行。它们具有较高的内部效度且允许精确控制，但可能因环境不自然而缺乏生态效度。

Field experiments take place in a natural setting. The IV is still manipulated, offering a balance between control and realism. However, there is less control over extraneous variables, and ethical issues such as informed consent may arise.

现场实验在自然环境中进行。自变量仍被操纵，在控制和真实之间取得平衡。然而，对外部变量的控制较少，且可能引发知情同意等伦理问题。

Natural and quasi-experiments: In a natural experiment, the IV is not manipulated by the researcher but occurs naturally (e.g., a policy change). In a quasi-experiment, the IV is a participant characteristic (e.g., gender) that cannot be randomly allocated. Both limit causal conclusions.

自然实验和准实验：自然实验中，自变量不由研究者操纵而是自然发生（如政策变化）。准实验中，自变量是无法随机分配的受试者特征（如性别）。两者对因果结论有所限制。

---

3. Experimental Designs | 实验设计

Independent groups design: participants are randomly allocated to different conditions. This avoids order effects, but participant variables (individual differences) can become confounds. Random allocation helps minimise this.

独立组设计：参与者被随机分配到不同条件。这避免了顺序效应，但参与者变量（个体差异）可能成为混淆变量。随机分配有助于将其最小化。

Repeated measures design: the same participants take part in all conditions. This controls participant variables, but introduces order effects (practice, fatigue, boredom). Counterbalancing (ABBA) can be used to reduce order effects.

重复测量设计：同一批参与者参加所有条件。这控制了参与者变量，但引入了顺序效应（练习、疲劳、厌倦）。可通过平衡法（ABBA）减少顺序效应。

Matched pairs design: participants are matched on key characteristics (e.g., IQ, age) and then one from each pair is assigned to each condition. This reduces participant variables without order effects, but matching is time-consuming and never perfect.

配对设计：参与者在关键特征（如智商、年龄）上进行匹配，然后每对中的一人被分配到不同条件。这减少了参与者变量且无顺序效应，但匹配耗时且难以完美。

---

4. Variables and Operationalisation | 变量与操作化

Operationalisation means defining the IV and DV in precise, measurable terms. For example, ‘aggression’ could be operationalised as the number of times a participant hits a bobo doll. Without clear operationalisation, the experiment cannot be replicated.

操作化指用精确、可测量的方式定义自变量和因变量。例如，“攻击性”可操作化为参与者击打波波玩偶的次数。没有明确的操作化，实验就无法被重复。

Extraneous variables (EVs) are any variables other than the IV that might affect the DV. Situational variables (e.g., noise, temperature) and participant variables (e.g., mood, IQ) are common EVs. If an EV systematically changes with the IV, it becomes a confounding variable.

外部变量是指除自变量外可能影响因变量的任何变量。情境变量（如噪音、温度）和参与者变量（如情绪、智商）是常见的外部变量。如果外部变量与自变量系统性地变化，则成为混淆变量。

Confounding variables undermine the internal validity of the experiment because the researcher cannot be sure whether the IV or the confound caused the change in the DV. Careful experimental design aims to control or eliminate confounds.

混淆变量损害实验的内部效度，因为研究者无法确定是因变量还是混淆变量导致了因变量的变化。谨慎的实验设计旨在控制或消除混淆。

---

5. Controlling Extraneous and Confounding Variables | 控制混淆与外部变量

Random allocation is the most effective way to control participant variables in independent groups designs. Each participant has an equal chance of being in any condition, spreading individual differences equally.

随机分配是独立组设计中控制参与者变量最有效的方法。每名参与者有均等机会进入任一条件，从而使个体差异均匀分布。

Standardisation involves keeping the procedure exactly the same for all participants. This includes standardised instructions, timings, and settings. Any change in procedure can introduce situational EVs.

标准化要求对所有参与者实施完全相同的程序，包括标准化指导语、时间和设置。程序的任何变化都可能引入情境外部变量。

Counterbalancing is used in repeated measures to distribute order effects across conditions. For example, ABBA counterbalancing: half the participants do condition A then B, the other half do B then A.

平衡法用于重复测量中以分散顺序效应。例如，ABBA平衡法：一半参与者先做A条件

Published by TutorHao | AS Psychology Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）