📚 IGCSE Cambridge Psychology: Mastering the Experimental & Practical Exam | IGCSE 剑桥心理学：掌握实验与实践考核要点
Whether you are preparing for Paper 4 (Alternative to Coursework) or tackling research methods questions across the assessment, the experimental and practical component of IGCSE Cambridge Psychology requires a clear understanding of the scientific process. This guide breaks down the key assessment points, helping you design, conduct, evaluate, and write about psychological experiments with confidence.
无论你是在备考 Paper 4（替代课程作业）还是应对试卷中有关研究方法的问题，IGCSE 剑桥心理学的实验与实践环节都要求你对科学研究过程有清晰的理解。本指南将分解关键考核要点，帮助你自信地设计、实施、评估和撰写心理学实验。
1. Understanding the Assessment Objectives | 理解评估目标
The IGCSE Psychology syllabus tests three main areas: knowledge and understanding of concepts, application of research methods, and evaluation of studies and data. In the experimental context, you must demonstrate the ability to formulate testable hypotheses, identify variables, select appropriate designs, and critically assess strengths and weaknesses of methodology.
IGCSE 心理学教学大纲测试三个主要领域：对概念的知识与理解、研究方法的运用，以及评估研究及数据的能力。在实验情境中，你必须展示出提出可检验假设、识别变量、选择适当设计，并批判性地评估方法优劣的能力。
You should know the difference between an aim and a hypothesis, and how to write both. An aim states the purpose of the investigation, while a hypothesis is a precise, testable statement predicting the relationship between variables. Both will be examined in practical-style questions.
你需要知道研究目标与假设的区别，以及如何撰写两者。目标陈述调查的目的，而假设是一个精确、可检验的陈述，预测变量之间的关系。两者都会在实践类问题中考查。
2. Formulating Hypotheses and Aims | 提出假设与目标
A well-written experimental hypothesis can be directional (one-tailed) or non-directional (two-tailed). A directional hypothesis predicts the specific direction of the effect, e.g. 'Participants who listen to music while studying will score higher on a memory test than those who study in silence.' A non-directional hypothesis simply states there will be a difference, without specifying direction.
一个好的实验假设可以是有方向的（单尾）或无方向的（双尾）。有方向假设预测效应的具体方向，例如“边听音乐边学习的参与者在记忆测试中的得分高于在安静环境中学习的参与者”。无方向假设只说明存在差异，而不指明方向。
The null hypothesis always states there will be no significant difference or relationship, and it is the statement you test statistically. For IGCSE practical exams, you need to be able to write both experimental and null hypotheses clearly.
零假设总是陈述不会有显著差异或关系，它是你进行统计检验时的陈述。在 IGCSE 实践考试中，你需要能够清晰地写出实验假设和零假设。
3. Variables: IV, DV and Control | 变量：自变量、因变量与控制变量
The independent variable (IV) is what the experimenter manipulates or changes. The dependent variable (DV) is what is measured. Operationalising variables means stating exactly how the IV and DV will be manipulated or measured – for example, 'number of words correctly recalled' rather than just 'memory'.
自变量 (IV) 是实验者操纵或改变的因素。因变量 (DV) 是被测量的结果。操作化变量意味着要清楚说明如何操纵 IV 和测量 DV——例如，用“正确回忆的单词数量”而不只是“记忆力”。
Control variables are factors kept constant to prevent them from affecting the DV. Common examples include room temperature, time of day, task instructions, and participant characteristics. A practical question may ask you to identify two control variables and explain why they matter.
控制变量是保持恒定的因素，以避免它们影响因变量。常见的例子包括室温、一天中的时间、任务指令和参与者特征。实践题可能会要求你找出两个控制变量并解释其重要性。
4. Experimental Designs | 实验设计
The three main experimental designs are independent groups, repeated measures, and matched pairs. In independent groups, different participants are used in each condition of the IV. This avoids order effects but may be affected by participant variables.
三种主要的实验设计是：独立组设计、重复测量设计和匹配对设计。在独立组设计中，不同的参与者被分配到自变量的各个条件。这避免了顺序效应，但可能受到参与者变量的影响。
In repeated measures, the same participants take part in all conditions. This controls for participant variables but introduces order effects like practice or fatigue. Counterbalancing can be used to reduce order effects.
重复测量设计中，相同的参与者参与所有条件。这控制了参与者变量，但引入了练习或疲劳等顺序效应。可使用平衡法来减少顺序效应。
Matched pairs design uses different but similar participants. Participants are matched on a relevant characteristic, then one from each pair is placed in each condition. This reduces participant variables without order effects but is time-consuming.
匹配对设计使用不同但相似的参与者。参与者在相关特征上进行匹配，然后每对中的一人被分配到每个条件。这减少了参与者变量而没有顺序效应，但耗时较长。
- Strengths to remember: Independent groups – quick, no order effects; Repeated measures – fewer participants, controls participant variables; Matched pairs – best control, no order effects.
- 需记住的优点：独立组——快速，无顺序效应；重复测量——需要较少参与者，控制参与者变量；匹配对——控制最佳，无顺序效应。
5. Sampling Methods | 抽样方法
Sampling techniques include random, opportunity, volunteer (self-selected), and stratified sampling. Random sampling gives every member of the target population an equal chance of selection, reducing bias. However, it is often difficult to obtain a complete list of the population.
抽样技术包括随机抽样、机会抽样、志愿者（自选）抽样和分层抽样。随机抽样给目标总体中的每个成员相等的入选机会，减少了偏差。然而，通常很难获得完整的总体名单。
Opportunity sampling uses people who are available and willing; it is easy and quick but may be unrepresentative. Volunteer sampling relies on participants responding to an advert, leading to a certain type of volunteer. Stratified sampling involves dividing the population into subgroups and randomly selecting from each in proportion, which enhances representativeness.
机会抽样使用现成且愿意参与的人；简便快捷但可能不具代表性。志愿者抽样依赖于参与者回应广告，导致某一类型的志愿者出现。分层抽样将总体分成多个子群，并按比例从每个子群中随机选取，增强了代表性。
In the practical exam, you may be asked to suggest a suitable sampling method and justify your choice, linking it to the aim of the study.
在实践考试中，你可能会被要求建议一种合适的抽样方法并证明你的选择，将之与研究的目地联系起来。
6. Ethical Considerations | 伦理考量
All psychological experiments must follow ethical guidelines: informed consent, right to withdraw, deception must be avoided or justified, protection from harm, confidentiality, and debriefing. IGCSE exam questions frequently ask you to either identify ethical issues in a scenario or suggest how to deal with them.
所有心理学实验都必须遵循伦理准则：知情同意、退出权、避免欺骗或在必须时给出合理解释、保护参与者免受伤害、保密、事后说明。IGCSE 考题经常要求你在一种情境中识别伦理问题，或提出如何处理这些问题。
For example, if a study involves mild deception, you might write: 'Participants should be fully debriefed after the study, explaining the true purpose and offering the chance to withdraw data.' Where consent cannot be obtained beforehand (e.g. field experiment), you should propose gaining post-hoc consent and protecting anonymity.
例如，如果一项研究涉及轻度欺骗，你可以写道：“研究结束后，应向参与者充分进行事后说明，解释真实目的，并提供撤回数据的机会。” 在无法事先获得同意的情况下（如现场实验），你应当提出事后补获同意并保护匿名性。
7. Data Collection Techniques | 数据收集技术
IGCSE Psychology practical questions may ask you to describe how to collect data using self-report methods (questionnaires, interviews) or observational methods (structured, naturalistic, participant observation). You must consider design features such as open vs closed questions, rating scales, or behavioural categories.
IGCSE 心理学实践题可能会要求你描述如何使用自我报告法（问卷、访谈）或观察法（结构化观察、自然观察、参与观察）来收集数据。你必须考虑设计特征，例如开放式与封闭式问题、评定量表或行为类别。
For interviews, note the difference between structured, semi-structured and unstructured. For observations, operationalise behavioural categories so that observers can tally events reliably. Inter-observer reliability can be checked to improve data quality.
对于访谈，要注意结构化、半结构化和非结构化访谈之间的区别。对于观察，要使行为类别操作化，以便观察者可以可靠地计数事件。可以检查观察者间信度来提高数据质量。
8. Controlling Extraneous Variables | 控制额外变量
Extraneous variables are any variables other than the IV that could affect the DV. If not controlled, they become confounding variables. Common types include situational variables (e.g. noise, time of day) and participant variables (e.g. mood, intelligence).
额外变量是除自变量以外可能影响因变量的任何变量。如果不加控制，它们就成为混淆变量。常见类型包括情境变量（例如噪音、时间）和参与者变量（例如情绪、智力）。
Standardisation of procedures is essential: using the same instructions, materials, and environment for all participants. In a practical description, you should mention how you will keep the testing room quiet, ensure instructions are read from a script, and use the same timing devices.
程序标准化至关重要：对所有参与者使用相同的指导语、材料和环境。在描述实践方案时，你应提及如何保持测试房间安静、确保指导语按脚本宣读，并使用相同的计时设备。
Random allocation is used in independent groups designs to distribute participant variables evenly. Counterbalancing is used in repeated measures. Both must be explained clearly in exam answers.
随机分配用于独立组设计，以均匀分布参与者变量。平衡法用于重复测量设计。在考试答案中，两者都必须清楚解释。
9. Data Analysis and Drawing Conclusions | 数据分析与结论
Descriptive statistics include measures of central tendency (mean, median, mode) and measures of spread (range, standard deviation). You should know how to calculate these and when to use each. For example, the median is better than the mean if there are extreme scores.
描述统计包括集中趋势测量（平均数、中位数、众数）和离散程度测量（全距、标准差）。你应当知道如何计算这些指标以及何时使用它们。例如，如果存在极端分数，中位数优于平均数。
e hypothesis. A common task is to write a conclusion supported by data, using phrases like ' ean scores between Condition A (mean = 15) and Condition B (mean = 12), suggesting that...'.
IGCSE 考题常涉及解读表格或图表。你必须识别趋势、比较条件，并将结果与假设联系起来。一个常见的任务是写出有数据支持的结论，使用诸如“结果显示条件 A（平均分 = 15）与条件 B（平均分 = 12）之间的平均分存在差异，表明……”这样的语句。
Paragraph-style conclusions should not go beyond the data; avoid claiming causes unless the experiment was well-controlled. Mention whether the null or experimental hypothesis can be upheld.
段落式结论不应超出数据；除非实验控制良好，否则避免宣称因果关系。要提及是零假设还是实验假设得到了支持。
10. Evaluating Experiments: Reliability and Validity | 实验评估：信度与效度
Reliability refers to consistency. If the experiment were repeated, would similar results be obtained? You can improve reliability through standardisation, clear operational definitions, and pilot studies. Validity concerns whether the experiment measures what it claims to measure. Internal validity asks if the IV really caused the DV change, while external validity relates to generalisability (ecological validity, population validity).
信度指一致性。如果重复这个实验，是否会得到类似的结果？你可以通过标准化、清晰的操作定义和预实验来提高信度。效度涉及实验是否测量了它所声称要测量的内容。内部效度询问自变量是否确实引起了因变量的变化，外部效度则关系到推广性（生态效度、总体效度）。
In practical evaluations, point out realistic weaknesses, e.g. 'The use of a questionnaire may have low internal validity because participants might give socially desirable answers rather than their true opinions.' Always offer a specific improvement.
在实际评估中，要指出真实的不足之处，例如“使用问卷可能内部效度较低，因为参与者可能给出社会赞许性回答而非真实意见。” 总要提出具体的改进方法。
A good evaluation weighs up strengths and limitations. Use terms like 'however', 'on the other hand', and link to the study you are critiquing.
一个好的评估会权衡优点和局限。使用诸如“然而”、“另一方面”这样的词语，并将之与你正在评论的研究联系起来。
11. Practical Exam Tips | 实践考试技巧
When answering the experimental scenario question, read the stem carefully and underline key words. Structure your answer logically: aim, hypothesis, IV, DV, design, sample, procedure, controls, ethical issues, data analysis, and expected results. Many mark schemes reward this clear structure.
在回答实验情境题时，仔细阅读题干并划出关键词。按照逻辑组织你的答案：目标、假设、自变量、因变量、设计、样本、程序、控制、伦理问题、数据分析和预期结果。许多评分方案都奖励这种清晰的结构。
Use precise psychological terminology – 'manipulate the IV', 'measure the DV', 'counterbalance conditions', 'standardised instructions'. Avoid vague language. If asked to 'write a detailed procedure', imagine you are telling another researcher exactly what to do, step by step.
使用精准的心理学术语——“操纵自变量”、“测量因变量”、“平衡条件”、“标准化指导语”。避免模糊语言。如果被要求“写出详细程序”，想象你在一步一步地告诉另一位研究者该做什么。
Manage your time. In Paper 4, allocate roughly 25–30 minutes for the experiment design question. Plan your answer in bullet points first if permitted, or mentally outline the key sections. Leave a few minutes to check you have addressed all parts of the question.
管理好时间。在 Paper 4 中，大约分配 25–30 分钟给实验设计题。如果允许，先以要点形式规划你的答案，或在脑中列出关键部分。留出几分钟检查你是否回答了问题的所有部分。
12. Summary of Key Command Words | 关键指令词总结
| Command Word | What It Asks | Example in Psychology |
| Identify | Name or state something. | Identify the independent variable. |
| Describe | Give a detailed account. | Describe how the procedure was standardised. |
| Explain | Give reasons, say why. | Explain why a matched pairs design was used. |
| Suggest | Apply knowledge to a new situation. | Suggest how to improve validity. |
| Evaluate | Give strengths and weaknesses. | Evaluate the sampling method used. |
Understanding these command words prevents misreading the question. Always tailor your answer to exactly what the command word requires – a 'describe' answer will not score marks for explanation unless you add reasons.
理解这些指令词可以防止误读题目。始终让你的答案精确匹配指令词的要求——“描述”类型的答案如果不加上原因，就不会因为解释而得分。
Published by TutorHao | 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