Name: main effects and interactions in factorial designs
Uploaded: 2023-04-30T06:36:24.000Z
Duration: 6 min 58 s
Channel: JoVE

1. 研究主题/科学问题的提出
<ol>
	<li>研究问题：人类行为具有复杂性，个体的思想和行为往往是多种原因或因素共同作用的结果。例如，如果你想了解为何有些人更擅长解读他人的面部表情，那么有许多因素可能影响这种能力。</li>
	<li>采用析因设计的理由：与其逐一检验可能的解释，不如使用析因设计，这种设计的独特之处在于，它允许在同一项研究中同时检验两个或更多潜在影响因素。</li>
	<li>析因设计的优势：通过同时而非依次检验影响因素，可以节省时间。这种方法使研究人员能够减少所需参与者数量，并揭示不同因素是否以特定方式共同作用，从而影响结果。</li>
</ol>
2. 关键变量
<ol>
	<li>变量 = 研究中任何会发生变化的因素</li>
	<li>自变量 = 原因，或研究者为了检测参与者变化而操纵或改变的因素
	<ol>
		<li>根据研究者的文献检索，她认为个体的自尊（i.e.，个体对自己作为一个人的积极或消极评价）和自我意识（i.e.，个体对自己思想和情感的觉察程度）是两个值得研究的自变量</li>
	</ol>
	</li>
	<li>因变量 = 效应，或研究者在参与者身上测量的结果或指标
	<ol>
		<li>根据研究问题，准确检测或解读非语言交流的能力是因变量。</li>
	</ol>
	</li>
</ol>
3. 研究假设
<ol>
	<li>主效应假设定义：在因子设计中，每次只关注一个自变量，而忽略其他自变量的假设。
	<ol>
		<li>主效应1：具有高自尊的个体在判断眼神表情时的准确性高于具有低自尊的个体。</li>
		<li>主效应2：具有高自我意识的个体在判断眼神表情时的准确性高于具有低自我意识的个体。</li>
	</ol>
	</li>
	<li>交互作用假设定义：预测一个自变量会改变另一个自变量对因变量影响的假设。
	<ol>
		<li>交互作用：自尊对准确识别非语言交流能力的影响，在具有高自我意识的个体中会增强，而在具有低自我意识的个体中会减弱。</li>
	</ol>
	</li>
</ol>
4. 定义变量
<ol>
	<li>自尊：为了操纵自尊这一自变量，研究人员将向参与者提供有关其准确识别欧洲国家能力的虚假反馈。</li>
	<li>自我意识：为了操纵自我意识这一自变量，将参与者置于镜子前。此方法借鉴自以往的研究。1</li>
	<li>非语言沟通解码的准确性：为了测量非语言沟通解码准确性这一因变量，向参与者展示多组眼睛图片，并要求他们识别出所表达的正确情绪。这也是一种已被确立的测试方法。2</li>
</ol>
5. 建立实验条件
<ol>
	<li>自尊：要求参与者在 2 分钟内尽可能多地列举出他们能想到的欧洲国家。根据条件提供反馈：
	<ol>
		<li>高自尊条件：参与者被告知他们的成绩位于前 10%，且其表现为“优异且高于平均水平”。</li>
		<li>低自尊条件：参与者被告知他们的成绩位于后 50%，且其表现为“较差且低于平均水平”。</li>
	</ol>
	</li>
	<li>自我意识
	<ol>
		<li>高自我意识：在地理测验期间，让参与者坐在镜子前（镜子应尽可能显得自然且不显眼）</li>
		<li>低自我意识：在地理测验期间不放置镜子。</li>
	</ol>
	</li>
	<li>条件组合：采用被试间因子设计，每位参与者接受一种独立变量的组合（表 1）。本研究中的四种可能组合为： 
	a) 高自尊/高自我意识 
	b) 低自尊/高自我意识 
	c) 高自尊/低自我意识 
	d) 低自尊/低自我意识</li>
</ol>
<img alt="自尊与自我意识矩阵图；高低分类；心理分析。" src="/files/ftp_upload/10058/10058table1.jpg" data-altupdatedat="1761830439000" data-alt="表 1"> 
表 1. 析因设计。 展示的是 2 × 2 设计中各因素可能的组合方式。
6. 测量因变量（解码非言语交流的准确性）
<ol>
	<li>测验
	<ol>
		<li>让参与者完成测验；在展示过程中务必鼠标悬停在图片上，以更清晰地显示眼睛。</li>
		<li>得分 = 正确题数总和，最终得分为 0-36 分</li>
	</ol>
	</li>
</ol>
7. 开展研究
<ol>
	<li>实验环境 = 配备计算机并设有供受试者面对镜子就座空间的研究实验室</li>
	<li>知情同意
	<ol>
		<li>在研究实验室中，接待参与“文化面孔”研究的受试者。</li>
		<li>进行知情同意说明：“正如您在知情同意书中所读到的，本研究涉及对非语言交流和文化认知的感知。本研究的目的是了解人们如何解读面部表情。您还将了解到参与本研究可能存在的风险和益处，并且您可随时自由退出。”</li>
	</ol>
	</li>
	<li>随机分组
	<ol>
		<li>根据受试者的条件组合（高自尊/高自我意识；低自尊/高自我意识；高自尊/低自我意识；低自尊/低自我意识），随机分配实验材料包</li>
	</ol>
	</li>
	<li>实施实验
	<ol>
		<li>自我意识
		<ol>
			<li>根据实验条件，受试者将坐在镜子前或不面对镜子就座。</li>
		</ol>
		</li>
		<li>自尊水平
		<ol>
			<li>向受试者发放一张包含50个空格的纸张，要求其在接下来的2分钟内尽可能多地列出欧洲国家名称。启动计时器。在分析该受试者结果并与以往参与者数据比较后，根据其实验条件，在一张纸上提供相应的反馈信息</li>
		</ol>
		</li>
		<li>对面部图片吸引力的评分
		<ol>
			<li>让受试者坐在计算机前完成在线测验的网络版本（<a href="http://www.questionwritertracker.com/quiz/61/Z4MK3TKB.html">http://www.questionwritertracker.com/quiz/61/Z4MK3TKB.html</a>）。该测验内容为：“针对每一对眼睛图片，请选择最能描述图中人物所思或所感的词语。” 统计每位受试者在36题中答对的题目数量。</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>实验后说明
	<ol>
		<li>向受试者解释本研究的真实目的。宣读实验后说明材料：“感谢您的参与。我们的研究探讨了自尊和自我意识对人们感知模糊面部表情的影响。我们假设，与高自尊和高自我意识的个体相比，低自尊和低自我意识的个体会将面部表情解读为更具评判性和攻击性。您有任何问题吗？”</li>
		<li>说明实验中的欺骗环节
		<ol>
			<li>解释如下：“我们希望获得受试者自然真实的行为表现，而非其认为被期待的表现。如果受试者事先知晓本研究的真实目的和假设，他们可能会刻意调整行为以迎合实验者的预期，从而导致表现失真。为避免这一问题，实验者有必要向受试者提供虚假信息。在本实验中，我们通过向您提供地理测验的虚假反馈来实现这一点。实际上，我们并未以任何方式对您的测验进行评分。您所收到的反馈是基于随机分配的结果，绝不代表您真实的能力水平。这一设计是必要的，以确保每位受试者都会经历短暂的自尊提升或降低。由于本研究的设计方式，受试者相信反馈内容是十分自然的反应，但请放心，这些反馈并不真实。”</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>

析因设计常用于心理学实验。这种设计适用于多种研究主题，范围从药物对恐惧反应的影响，到不同水平的压力与运动类型之间的相互作用。

析因实验

The Factorial Experiment

来源：<a href="https://www.jove.com/author/Gary_Lewandowski">Gary Lewandowski</a>、Dave Strohmetz 和 Natalie Ciarocco —— 蒙茅斯大学实验室

析因设计是一种常见的实验类型，包含两个或更多的自变量。本视频演示了一种2 × 2析因设计，用于探讨自我意识和自尊如何影响个体解读非言语信号的能力。本视频将引导学生掌握析因设计的基本知识，包括析因设计的本质及其与其他设计的区别、析因设计的优势、交互作用的重要性与本质、主效应与交互作用的假设，以及如何开展一项析因实验。

在收集了136人的数据后，进行了双因素方差分析（ANOVA），以检验两个主效应及其交互作用。如图1所示，与假设的模式相反，当参与者自我意识较高时，他们在自尊水平较低的情况下判断更准确；然而，当他们的自我意识较低时，则在自尊水平较高时判断更准确。
除了影响解读他人眼神含义的能力外，较低的自我意识还可能导致低自尊者体验到更多负面情绪，例如感到抑郁。
如果研究人员能够确定导致更准确理解非语言交流的因素，那么个体或许就能够学会更好地解读他人的非语言信号。试想一下，在哪些情境中准确理解一个人的表情会带来帮助：从事销售工作、参与体育运动、面试求职者，或是相亲约会。事实上，非语言交流无处不在，而找到更准确解读它的方法只会带来益处。
<img alt="在意识条件下，高低自尊者的非言语解码得分比较柱状图。" src="/files/ftp_upload/10058/10058fi...

来源：蒙茅斯大学 Gary Lewandowski、Dave Strohmetz 和 Natalie Ciarocco 实验室

析因设计是一种常见的……

当研究人员需要在同一项研究中操控两个或更多自变量并测量其对单一因变量的影响时，会采用析因设计。例如，如果研究人员想要了解为什么有些人更善于解读他人的面部表情，他们就必须考察可能影响这种能力的多种因素。与一次实验仅检验一个潜在影响因素不同，析因设计允许在一次实验中同时考察多个变量。这种设计所需的受试者更少，并且能够揭示不同因素之间是否存在特殊的交互作用，从而影响结果。本视频演示了如何设计并实施一项简单的因子实验，以探讨自我意识和自尊如何影响个体解读非语言信号的能力，以及如何分析实验结果并考察采用该设计的其他案例。本实验采用 2×2 因子设计，包含两个自变量——自我意识和自尊——每个自变量均有高和低两个水平。为了操控自我意识水平——即个体对自己思想和情感的觉察程度——高自我意识组的参与者需在镜子前完成一项地理知识测验，而低自我意识组的参与者则在没有镜子的环境中完成同一测验。为了同时操控自尊——即个体对自我价值的积极或消极评价——参与者会收到关于地理测验的虚假反馈。高自尊组的参与者被告知，他们的得分位于前10%，表现优异且高于平均水平；而低自尊组的参与者则被告知，他们的得分位于后50%，表现较差且低于平均水平。因此，需注意参与者将接受四种可能组合中的一种：高自尊/高自我意识；低自尊/高自我意识；高自尊/低自我意识；或低自尊/低自我意识。在收到反馈后，参与者需要观察多组眼睛图像，并识别出所表达的正确情绪。在此情况下，因变量是解码非语言交流的准确性。由于实验设计较为复杂，因此提出了多个假设。主效应假设——即关注单一自变量影响的假设——认为，处于各条件高水平组的个体在判断眼部表情时将比处于低水平组的个体更为准确。相比之下，交互作用假设——即某一自变量会改变另一变量对因变量影响的假设——认为，自我意识水平较高的个体，其自尊对准确识别非言语交流能力的影响会增强；而对于自我意识水平较低的个体，这种影响则会减弱。在参与者到达之前，将包含四种条件组合的每组材料包随机排列，以确保分组完全基于随机分配。实验开始时，在实验室与参与者会面。向其提供知情同意书，简要说明研究内容、实验流程、参与可能带来的风险与益处，以及随时退出实验的权利。根据指定的自我意识条件，指导参与者坐在单向镜前，若需允许其看到自身反射，则打开百叶窗；若需防止其自我观察，则关闭百叶窗，随后让其参加测验。接下来，给每位参与者发放一张包含50个空格的纸张，要求他们在接下来的2分钟内尽可能多地列出欧洲国家的名称。在告知参与者您正在将其结果与以往参与者的结果进行比较后，根据其随机分配的条件，向其提供书面反馈。然后，让参与者坐在计算机前完成另一项测验，该测验要求参与者根据模糊的眼部图像辨别面部表情。实验结束时，向参与者说明研究的性质，以及为何在实验开始前无法告知研究的真实目的。为了分析自尊和自我意识如何影响解读非言语表情的能力，需计算每组眼动解释测验得分的平均值，并按不同条件绘制均值图。为了确定是否存在组间差异，需进行双因素方差分析，以揭示任何主效应或交互效应。在此情况下，自我意识的影响取决于自尊水平。与假设的模式相反，值得注意的是，具有高自我意识和低自尊的参与者在解读非语言表情方面更为准确。然而，当处于低自我意识状态下时，具有高自尊的参与者表现出了更高的准确性。现在您已经熟悉了如何设计和实施一个 2×2 析因实验，接下来让我们来看一些采用这种设计的其他示例。在一项研究中，测量了在低概率或高概率接受电击期间惊吓反射的增强情况。另一个自变量，例如给予酒精或安慰剂，可用于研究电击强度和酒精对惊吓反应的影响。在另一个例子中，考虑不同水平的压力如何与所进行的运动类型相互作用。为了同时测试所有这些条件，需要采用一个2×2的析因设计。或许在另一种情况下，研究者希望探究学生在屏幕测试与纸质测试中的表现差异，而参与者的性别可能会影响测试成绩。此时，仍需采用二乘二的析因设计来进行同时分析。您刚刚观看了 JoVE 关于析因实验设计的介绍视频。现在，您应该已经很好地掌握了如何设计和实施2×2析因实验，以及如何对这类研究中常见的结果进行统计分析。您还了解了若干使用2×2析因设计具有优势的实例。感谢观看！

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main effects and interactions in factorial designs

A factorial design uses two or more independent variables in one experiment. A 2 x 2 factorial design is a common example. It lets students see how more than one factor can shape an outcome at the same time.

This experiment uses self-awareness and self-esteem as the two independent variables. It explores whether they affect the ability to decipher nonverbal signals. The design also shows how a factorial experiment differs from other designs and why it can be useful.

A key part of this topic is the interaction, which happens when the effect of one independent variable depends on the other. The video also explains main effect and interaction hypotheses. It then shows how to conduct a factorial experiment and how to think through the results.

Main Effects and Interactions in Factorial Designs

main-effects-and-interactions-in-factorial-designs

from theory to design: the role of creativity in designing experiments

from-theory-to-design-the-role-of-creativity-in-designing-experiments

Creative Study Design in Social Psychology

Creative study design helps social psychology researchers test ideas about human thought, emotions, and behavior. Many research questions begin with a theory that suggests a possible explanation for everyday life. Some of those ideas are hard to study directly, so researchers need a careful plan to test them. One example is a theory about Facebook perception. Researchers asked whether a person’s image on Facebook is influenced by the appearance and comments of that person’s Facebook friends.

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Mundane Realism in Lab Experiments

Mundane realism helps lab experiments feel like real life. It is used when researchers want a setting that matches how people normally behave. In some studies, the real world is the best place to observe behavior directly. For example, voting behavior is easier to study by watching people vote. But real-world research is not always ethical or practical. A lab gives researchers more control over the setting. That control helps them identify the exact variables that may influence an outcome. To...

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Psychology Research Methods in Practice

Psychology research methods are shown through real experiments in this JoVE K12 collection. The pages let high school students watch studies from start to finish. They also show the experiments in their natural setting, inside the actual research process. The collection is useful because experimental psychology can be hard to connect to from a textbook alone. These videos give students exposure to more than a dozen topics they may not otherwise see. They can help bring abstract ideas to life...

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Testing Stress Manipulations Before the Study

Pilot testing helps researchers check whether a manipulation works before they run the main study. In psychology, researchers need study experiences that are consistent, or reliable, and authentic, or valid. Pilot testing lets them try out a manipulation first and see if it produces the intended effect. This study focuses on acute stress, which is short-term stress caused during a task. The researchers compared three ways to create that stress. They tested static, a ticking clock, and a crying...

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A simple experiment uses a two-group design to test a cause-and-effect relationship between two variables. In this setup, a researcher compares two groups to see whether one factor changes the outcome. The video follows a research question about how physiological arousal, or excitement, influences perceived attraction. It shows how an idea becomes a testable idea and how a hypothesis is formed. The experiment variables are identified, and experimental conditions and controls are created. The...

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Testing Multiple Conditions in One Study

A multi-group experiment tests three or more conditions of the same independent variable. It lets researchers compare how each condition affects the outcome they measure. In this study, the conditions examine different interethnic ideologies and their effects on feelings about diversity and actions toward an out-group member. The video also shows how to tell levels in a variable apart and how to choose common study conditions. These can include placebo and empty-control conditions, which help...

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Repeated-Measures Study with Counterbalancing

A repeated-measures study uses the same participants in every condition of an experiment. In this design, each person receives every level of the independent variable. A simple example is a candy taste test, where each participant tastes and rates each type of candy. This psychology experiment looks at how motivational messages affect willingness to exert physical effort. The message types include hard work, self-affirmation, outcomes, and positive affect. Each participant reads all four...

the factorial experiment

A factorial design uses two or more independent variables in one experiment. A 2 x 2 factorial design is a common example. It lets students see how more than one factor can shape an outcome at the same time. This experiment uses self-awareness and self-esteem as the two independent variables. It explores whether they affect the ability to decipher nonverbal signals. The design also shows how a factorial experiment differs from other designs and why it can be useful. A key part of this topic...

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self-report-vs-behavioral-measures-of-recycling

Behavioral Observation in Recycling Studies

Behavioral observation can give a more direct measure of recycling behavior than self-report. Self-report means asking people to describe their feelings, thoughts, or actions. In some cases, participants may not be fully honest. Observing what people actually do can help researchers measure behavior more accurately. This study uses a multi-group experiment to test whether feeling close to others leads to more positive attitudes toward environmental consciousness. Researchers measured the...

reliability in psychology experiments

Content Analysis and Reliability in Psychology

Reliability in psychology is important when researchers try to measure something that is hard to quantify. In content analysis, reliability helps show whether the measurement is consistent. The video uses a simple two-group design to show how this works. The example compares two cartoons, SpongeBob SquarePants and Caillou, to ask whether one has more inappropriate content than the other. The transcript also connects this topic to a recent Pediatrics study on 4-year-olds. That study found worse...

placebos in research

Yoga Expectations and the Placebo Effect

Yoga expectations can influence how researchers measure creativity. Clinical research often tests whether a treatment really works for a disorder or illness. A common challenge is that participants may already believe a treatment will help. Those expectations can affect the results and make it harder to tell what the treatment actually did. Yoga is a good example because it has many claimed benefits in the United States, including improved creativity. But it is not always clear whether yoga...

manipulating an independent variable through embodiment

manipulating-an-independent-variable-through-embodiment

Embodiment Effects in a Weight Experiment

Embodiment can affect how people think and act in an experiment. It is a research idea that says subtle physical experiences may influence thoughts without people realizing it. Researchers use this idea to see how a simple body sensation can change later judgments. Researchers often manipulate participants in one group so they have different thoughts, experiences, or feelings than people in other groups. Some manipulations are obvious, and others are subtle. In this study, the key physical...

experimentation using a confederate

Using Confederates in Social Experiments

Confederates are used in social experiments to help researchers study how people react in a controlled setting. A confederate is a person who seems like a normal participant but follows the researcher’s directions instead. This helps create conditions that feel natural while still keeping the experiment organized. The study shown here uses a two-group design to test imitation. Researchers asked whether participants were more likely to copy a person with more power than a person with similar...

experimental psychology

这个集合提供了一个框架, 观察心理实验是如何嵌入在实际的研究过程中, 从最初的研究设计开始到得出结论在一项研究。

Explore a 2 x 2 factorial design using self-awareness and self-esteem. Learn main effects, interactions, hypotheses, and how to conduct the experiment.

Main Effects and Interactions in Factorial Designs

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