📚 Year 11 CIE Psychology: Key Experimental and Practical Assessment Points | Year 11 CIE 心理学：实验/实践考核要点
The experimental method is central to CIE IGCSE Psychology (0475), providing the tools to establish cause-and-effect relationships through careful manipulation and control. A strong grasp of experimental design, variables, controls, sampling, ethics, and analysis is essential for success in Paper 2 (Research Methods) and any practical assessment. This guide distills the key points you must master, presented bilingually to deepen your understanding.
实验方法是 CIE IGCSE 心理学（0475）的核心，通过严谨的操纵与控制建立起因果关系。扎实掌握实验设计、变量、控制、抽样、伦理和分析，对在 Paper 2（研究方法）及所有实践考核中取得好成绩至关重要。本指南以双语提炼你必须掌握的要点，帮助你加深理解。
1. The Nature of the Experimental Method | 实验方法的本质
A true experiment involves the deliberate manipulation of one factor – the independent variable (IV) – to observe its effect on another factor – the dependent variable (DV). This allows researchers to infer causation rather than mere association.
真正的实验涉及有意操纵一个因素——自变量（IV），以观察它对另一个因素——因变量（DV）的影响。这使得研究者可以推断因果关系，而不仅仅是关联。
In CIE IGCSE Psychology, three types of experiments are emphasised: laboratory experiments (high control, artificial setting), field experiments (manipulation in a natural environment), and natural/quasi experiments (where the IV changes naturally and is not directly manipulated). Each type offers a different trade-off between internal validity and ecological validity.
在 CIE IGCSE 心理学中，强调三种实验类型：实验室实验（高度控制、人工环境）、现场实验（在自然环境中进行操纵）以及自然/准实验（IV 自然变化，不由研究者直接操纵）。每一种类型都在内部效度与生态效度之间做出不同的权衡。
All experiments must begin with a clear hypothesis – a testable prediction about the relationship between IV and DV. An experimental hypothesis can be directional (predicting the direction of the effect) or non-directional (simply predicting an effect exists). The null hypothesis always states that any observed difference or correlation is due to chance.
所有实验都必须从一个清晰的假设开始——一个关于 IV 与 DV 关系的、可检验的预测。实验假设可以是方向性的（预测效应的方向）或非方向性的（仅预测存在效应）。零假设则始终陈述所观察到的差异或相关是由偶然引起的。
2. Independent and Dependent Variables | 自变量与因变量
The independent variable (IV) is the condition or event the researcher systematically changes or manipulates. The dependent variable (DV) is the outcome that is measured to assess the effect of the IV.
自变量（IV）是研究者系统改变或操纵的条件或事件。因变量（DV）是评估 IV 影响时所测量的结果。
Operationalisation is the process of defining variables in precise, measurable terms. For example, 'ability to focus' could be operationalised as 'number of correct responses on a sustained attention task in one minute'. This specificity ensures the experiment can be replicated.
操作化就是以精确、可测量的方式定义变量的过程。例如，“专注能力”可以被操作化为“在一分钟内持续性注意任务中正确反应的数量”。这种具体性确保了实验可以被重复。
In an experimental hypothesis, the statement 'Participants who drink 200 ml of water will recall significantly more words from a list of 30 than those who drink no water' identifies the IV (water intake) and the DV (number of words recalled), while indicating direction.
在实验假设中，“饮用 200 毫升水的参与者从 30 个单词列表中回忆出的单词数量将显著多于不喝水的参与者”这一陈述明确了 IV（饮水量）和 DV（回忆出的单词数），并指出了方向。
3. Experimental Design: Independent Groups, Repeated Measures, and Matched Pairs | 实验设计：独立组、重复测量与配对设计
The way participants are allocated to conditions (design) directly influences the internal validity of an experiment. CIE expects you to compare three main designs, assessing their strengths and weaknesses:
参与者被分配到不同条件的方式（实验设计）直接影响实验的内部效度。CIE 要求你比较三种主要设计，评估它们的优缺点：
| Design / 设计 | Key Feature / 关键特征 | Advantage / 优点 | Disadvantage / 缺点 |
|---|---|---|---|
| Independent Groups / 独立组 | Different participants in each condition / 每种条件使用不同的被试 | No order effects / 无顺序效应 | Participant variables (e.g., age, IQ) can confound results / 被试变量（如年龄、智商）可能混淆结果 |
| Repeated Measures / 重复测量 | Same participants in all conditions / 所有条件使用相同的被试 | Controls participant variables perfectly / 完美控制被试变量 | Order effects (practice, fatigue) require counterbalancing / 顺序效应（练习、疲劳）需要通过对抗平衡来控制 |
| Matched Pairs / 匹配对 | Participants matched on relevant traits, then split into conditions / 被试按相关特质匹配后分配到不同条件 | Reduces participant variables and avoids order effects / 减少被试变量且避免顺序效应 | Very time-consuming; matching can never be perfect / 非常耗时；匹配永远无法做到完美 |
Counterbalancing is a technique used in repeated measures where half the participants experience Condition A first and the other half Condition B first. This spreads practice effects evenly across conditions, reducing their impact.
对抗平衡是在重复测量中使用的一种技术，让一半被试先接受条件 A，另一半先接受条件 B。这样可以将练习效应均匀分散到各条件中，减少其影响。
4. Controlling Extraneous and Confounding Variables | 控制外源变量与混淆变量
Extraneous variables (EVs) are any factors other than the IV that could influence the DV. When an EV systematically varies with the IV and distorts the results, it becomes a confounding variable. Rigorous control is essential to maintain internal validity.
外源变量（EVs）是除 IV 以外任何可能影响 DV 的因素。当某个 EV 与 IV 一起系统地变化并歪曲结果时，它就变成了混淆变量。严格的控制对维持内部效度至关重要。
Standardisation of procedures ensures every participant receives exactly the same instructions, materials, and time. Standardised scripts and pre-set timings reduce situational variables like noise or experimenter behaviour.
程序的标准化确保每位参与者接收到完全相同的指导语、材料和时长。标准化的脚本和预设的计时可以减少情境变量，例如噪音或主试行为。
Random allocation to conditions, whenever possible, distributes participant variables (e.g., motivation, intelligence) evenly across groups, making it unlikely they will systematically bias the DV. Single-blind and double-blind procedures help control for demand characteristics and investigator effects.
只要可能，随机分配参与者到不同条件可以将被试变量（如动机、智力）均匀分布到各组，使它们不太可能系统地偏向 DV。单盲和双盲程序有助于控制需求特征和主试效应。
5. Sampling Techniques and Their Impact | 抽样技术及其影响
The sample is the group of people who take part in a study, drawn from a target population. The sampling method determines how representative the sample is, affecting the generalisability of findings.
样本是参与研究的群体，从目标人群中抽取。抽样方法决定了样本的代表性，从而影响研究结果的普遍性。
Random sampling, where every member of the population has an equal chance of selection, tends to produce the most representative sample. Stratified sampling identifies subgroups (strata) and selects proportionally, ensuring specific groups are included.
随机抽样——人群中每个成员都有同等的被选中机会——往往能产生最具代表性的样本。分层抽样先确定子群体（分层），再按比例抽取，确保特定群体被包含在内。
Opportunity sampling selects whoever is readily available (e.g., students in a canteen). It is quick and economical but often biased, because the sample may share characteristics not found in the wider population. Volunteer (self-selected) sampling suffers from volunteer bias, as people who offer to participate may be more motivated or have strong opinions.
机会抽样选择最容易接触到的人（例如食堂里的学生）。它快捷、经济，但往往有偏差，因为样本可能具有广大人群中不存在的共同特征。志愿者（自选）抽样存在志愿者偏差，因为主动参与的人可能更有动机或持有强烈观点。
6. Ethical Considerations in Psychological Experiments | 心理学实验中的伦理考量
The British Psychological Society (BPS) guidelines, which CIE Psychology follows, set out clear ethical principles. You must be able to identify and apply these when designing or evaluating experiments.
CIE 心理学所遵循的英国心理学会（BPS）指南规定了明确的伦理原则。在设计或评估实验时，你必须能够识别并应用这些原则。
Informed consent means participants should know the purpose, procedures, and their rights before agreeing to take part. If deception is necessary, it must be justified and followed by a thorough debrief where the true aim is revealed and any questions are answered.
知情同意意味着参与者在同意参加前应知晓研究目的、程序以及他们的权利。如果欺骗不可避免，则必须证明其合理性，并在事后进行充分的脱敏说明，揭示真实目的并回答所有疑问。
Confidentiality protects participants' identity by avoiding the use of names in published reports; data should be anonymised. The right to withdraw allows participants to leave the study at any time without pressure, and their data can also be withdrawn afterwards. Researchers must protect participants from physical and psychological harm, ensuring that the risk of distress is no greater than in everyday life.
保密原则通过在发表的报告中避免使用姓名来保护参与者身份；数据必须匿名化处理。退出权利让参与者可以随时无压力地离开研究，之后他们还可以撤回自己的数据。研究者必须保护参与者免受身体和心理伤害，确保痛苦的风险不大于日常生活。
7. Data Collection Methods in Experiments | 实验中的数据收集方法
Even within an experimental design, researchers use various tools to record the DV. Common methods include observations, questionnaires, and interviews. Each can be structured differently to suit the aim of the study.
即使在实验设计中，研究者也会使用多种工具记录 DV。常见的方法包括观察、问卷和访谈。每种方法都可以根据研究目的进行不同的结构化设计。
Observations in a laboratory setting can use behavioural categories (a checklist of specific behaviours) to make coding more objective. Inter-observer reliability is then checked to ensure consistency. Unstructured observations may generate richer qualitative data but are harder to replicate.
实验室环境下的观察可以使用行为类别（一份具体行为的核查表），使行为编码更加客观。然后检查观察者间信度以确保一致性。非结构化观察可能产生更丰富的质性数据，但更难以重复。
Questionnaires with closed questions (e.g., rating scales 1-5) produce quantitative data that is easy to analyse statistically. Open questions yield qualitative data, allowing participants to express their thoughts in depth, but require more time to interpret. Interviews can be structured, semi-structured, or unstructured, balancing standardisation against depth of response.
封闭式问题的问卷（例如 1-5 的评分量表）产生量化数据，便于统计分析。开放式问题产生质性数据，让参与者深入表达想法，但解读起来更耗时。访谈可以是结构化、半结构化或非结构化的，在标准化与回答深度之间取得平衡。
8. Types of Data and Basic Analysis | 数据类型与基本分析
Quantitative data deals with numbers and quantities, allowing statistical testing. Qualitative data is non-numerical, rich in description, and often analysed for themes or patterns.
量化数据涉及数字和数量，可以进行统计检验。质性数据是非数字性的，富含描述，通常用于分析主题或模式。
Descriptive statistics summarise the main features of a data set. The mean (average), median (middle value), and mode (most frequent) are measures of central tendency. The range (maximum minus minimum) is a simple measure of dispersion and is affected by extreme scores.
描述性统计概括数据集的主要特征。平均数（均值）、中位数（中间值）和众数（出现频率最高）是集中趋势的度量。极差（最大值减最小值）是离散度的简单度量，易受极端分数影响。
Results are often displayed via bar charts (for discrete categories) or histograms (for continuous data). In CIE exam questions, you may be asked to sketch a graph or interpret a simple data table. Remember that a correlation between two variables does not imply causation – an experimental approach with proper controls is required to establish cause and effect.
结果通常通过条形图（用于离散类别）或直方图（用于连续数据）展示。在 CIE 考试题目中，你可能需要绘制简图或解读简单的数据表格。请记住，两个变量之间的相关并不意味着因果关系——只有经过恰当控制的实验方法才能确定因果关系。
9. Evaluating Experiments: Validity and Reliability | 实验评估：效度与信度
Validity refers to whether a study measures what it claims to measure. Internal validity asks if the changes in the DV are genuinely due to the IV, not confounding variables. External validity concerns the extent to which findings can be generalised beyond the study setting.
效度指研究是否测量了它声称要测量的东西。内部效度关注 DV 的变化是否确实由 IV 引起，而非混淆变量。外部效度则关注研究结果在多大程度上可以推广到研究环境之外。
Ecological validity is a subtype of external validity, referring specifically to how well the task, materials, and setting of a study mirror real-life situations. A highly controlled lab experiment may lack ecological validity, whereas a field experiment often has higher ecological validity.
生态效度是外部效度的一种亚型，特指研究的任务、材料与环境在多大程度上反映了现实生活情境。高度控制的实验室实验可能缺乏生态效度，而现场实验通常具有更高的生态效度。
Reliability is the consistency of a measurement. Inter-rater (inter-ob
Published by TutorHao | Year 11 Psychology Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图