Lecture 5&6 PSYCH2018

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Questions and Answers

Which design type compares different groups of subjects across levels of an independent variable?

Between-subjects design (correct)

Cross-sectional design

Within-subjects design

Matched random assignment

Which factor is NOT a threat to internal validity in studies with pretests and posttests?

Maturation

History

Regression to the mean

Measurement validity (correct)

What is the purpose of random assignment in experimental research?

To address the equivalent groups problem (correct)

To ensure participants are aware of their group

To eliminate participant bias

To establish a control group

Which issue is primarily addressed by counterbalancing in within-subjects designs?

Order effects Signup and view all the answers

What is a significant reason for using a control group in an experiment?

To provide a benchmark for measurement Signup and view all the answers

Which aspect of ethical subject pools is emphasized by the APA guidelines?

Participants must be treated well and complaints should be addressed. Signup and view all the answers

In within-subjects designs, carry-over effects are typically more problematic than which other type of effect?

Progressive effects Signup and view all the answers

Why is it necessary to control for confounding variables in a study?

They may obscure the true relationship between the independent and dependent variables. Signup and view all the answers

What is a characteristic of matched random assignment?

Participants are grouped based on similar characteristics. Signup and view all the answers

In the context of internal validity, what does attrition refer to?

The loss of participants during the study. Signup and view all the answers

What is an example of a manipulated independent variable?

The instructions given to participants during the task Signup and view all the answers

Which statement correctly distinguishes between experimental and control groups?

Experimental groups receive treatment while control groups have treatment withheld Signup and view all the answers

What problem arises from the presence of confounding variables in an experiment?

They create uncertainty about the cause of observed results Signup and view all the answers

Which of the following best describes internal validity?

The ability to control extraneous variables and establish cause-and-effect relationships Signup and view all the answers

According to Mill's Method of Agreement, which scenario illustrates this method?

Observing that all individuals who received treatment showed improvement Signup and view all the answers

What characterizes a subject variable in an experiment?

It represents a characteristic inherent to participants that cannot be changed Signup and view all the answers

Which of the following factors can threaten an experiment's external validity?

The specificity of the treatments used within the experiment Signup and view all the answers

Under what circumstances might external validity be deemed unimportant in research?

When the research focuses on a unique phenomenon Signup and view all the answers

What is the primary design type used in a longitudinal study?

Within-subjects design Signup and view all the answers

Which design combines elements of both cross-sectional and longitudinal studies?

Cohort sequential design Signup and view all the answers

What can be a consequence of the Hawthorne effect during a study?

Altered behaviors due to awareness of being studied Signup and view all the answers

Which bias refers to the influence of experimenter's expectations on participant behavior?

Experimenter bias Signup and view all the answers

What is one method to control for experimenter bias in research?

Using double blind procedures Signup and view all the answers

What is an important responsibility of participants in a research study?

Be actively involved in debriefing Signup and view all the answers

What implication does a large age difference in a cross-sectional study have?

Greater likelihood of cohort effects Signup and view all the answers

Which technique is used to minimize demand characteristics in research?

Effective deception Signup and view all the answers

What is the primary method used to equalize potential confounds across groups in an experiment?

Random Assignment Signup and view all the answers

Which design allows for comparisons within the same group of subjects?

Within-Subjects Design Signup and view all the answers

What is a key characteristic of dependent variables (DVs) in an experiment?

They represent behaviors that are measured throughout the study. Signup and view all the answers

Which scenario best exemplifies a ceiling effect in an experiment?

All participants score at the maximum on an easy task, obscuring differences. Signup and view all the answers

What type of order effect is specifically difficult to control and may influence results in a sequence of tasks?

Carry-over effects Signup and view all the answers

When using subject variables, what is a vital consideration for researchers?

It is impossible to determine causation between IV and DV. Signup and view all the answers

What method involves random sampling of all possible combinations of experimental conditions?

Partial Counterbalancing Signup and view all the answers

Which of the following is NOT a situation where matching might be preferred over random assignment?

High number of participants Signup and view all the answers

What is an essential aspect of statistical conclusion validity?

Applying the right statistical tests and drawing correct conclusions. Signup and view all the answers

What type of counterbalancing tests participants in every possible order at least once?

Complete counterbalancing Signup and view all the answers

Which statement best describes external validity?

It pertains to the generalization of findings to other contexts. Signup and view all the answers

Which of the following pairs represents manipulated and subject variables in Bandura's Bobo study?

Gender of participants; Type of exposure to violence. Signup and view all the answers

Which type of counterbalancing ensures that every condition occurs equally often in varying positions?

Latin square design Signup and view all the answers

In within-subjects designs, what is the major concern that researchers must address to ensure validity?

Control for individual differences Signup and view all the answers

What are floor effects in experimental research?

When tasks are excessively difficult, resulting in low scores from all participants. Signup and view all the answers

What can be inferred when using both manipulated and subject IVs in a study?

There may be confounding factors that complicate causality. Signup and view all the answers

Study Notes

Research in Psychology: Methods & Design

This is an eighth edition textbook for research in psychology
Introduces experimental research methods and design

Chapter 5: Introduction to Experimental Research

Chapter Objectives:
- Describe the impact of Woodworth's 1938 Experimental Psychology on how psychologists define experiments
- Define a manipulated independent variable and identify examples (situational, task, instructional)
- Distinguish between experimental and control groups
- Describe John Stuart Mill's rules of inductive logic and apply them to experimental and control groups
- Recognize confounding variables in experiments and understand why they hinder interpretation
- Identify independent and dependent variables in experiments
- Differentiate between manipulated and subject variables
- Understand interpretation issues when using subject variables
- Recognize factors reducing statistical conclusion validity
- Detail how construct validity applies to experimental design
- Distinguish between internal and external validity
- Describe factors influencing experimental external validity
- Recognize and describe threats to internal validity
- Understand the ethical guidelines for using subject pools

Chapter 6: Control Problems in Experimental Research

Chapter Objectives:
- Distinguish between between-subjects and within-subjects designs
- Explain how random assignment resolves equivalent groups problems in between-subjects designs
- Explain when matched random assignment should be used to create equivalent groups
- Understand when counterbalancing is needed to control for order effects in within-subjects designs
- Differentiate between progressive and carry-over effects in within-subjects designs
- Detail various forms of counterbalancing for situations with one or many repeated testing per condition
- Describe specific types of between- and within-subject designs in developmental psychology and their problems
- Explain how experimenter and participant biases arise and how to control them

Essential Features of Experimental Research

Establishing Independent Variables (IVs):
- Manipulated IVs (e.g., situational, task, instructional)
- Experimental groups (receive treatment)
- Control groups (treatment withheld)
Controlling Extraneous Variables (Confounds):
- Any uncontrolled variable that might influence results
- Table 5.1 (confounding example) displays how confounding variables can influence results
Measuring Dependent Variables (DVs):
- Dependent variables are behaviors measured
- Review measurement scales
- Recognize and control for ceiling and floor effects.
Subject Variables:
- Existing attributes of subjects (e.g., gender, age, personality)
- Example: Anxiety
  - Manipulated variable: inducing varying degrees of anxiety
  - Subject variable: selecting subjects with different degrees of anxiety
- Research example 7: cultural differences (European Americans vs. East Asians), gender differences.
- Figure 5.1 displays field dependance.
Drawing Conclusions with Subject Variables:
- With manipulated IVs, assume no confounds, IV causes DV.
- With subject variables, groups may differ in many ways, thus IV does not necessarily cause DV. Conclude only that groups differ from one another.
Using Both Manipulated and Subject IVs:
- Example: Bandura's Bobo doll study (Box 5.2): manipulated exposure to violence, subject was gender

The Validity of Experimental Research

Statistical Conclusion Validity:
- Proper statistical analyses & conclusions
Construct Validity:
- Well-defined independent and dependent variables
External Validity:
- Extent findings can generalize to other populations, environments, and time periods
Internal Validity:
- Extent study answers its research question; valid operational definitions, valid measurements, no confounds
Threats to Internal Validity:
- History, maturation, regression to the mean, testing, instrumentation
- Importance of using a control group
- Subject selection (Brady study, ulcers in executive monkeys), attrition

Creating Ethical Subject Pools

Part of the educational process
Must follow APA guidelines and be thoroughly described
IRB approval needed for projects
Treat students fairly, resolve complaints, no penalty for no-show.
Follow all aspects of APA ethics
Assess subject pool for appropriate participation.

Summary

Between- and within-subjects designs are used in experimental psychology
Control through random assignment, matching, counterbalancing (complete or partial) for order effects in within-subjects designs
Developmental designs have unique control issues
Researcher and participant bias need careful consideration.

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Description

Explore Chapter 5 of the eighth edition textbook on research methods in psychology. This chapter focuses on the principles of experimental research, including the definition of independent variables, the role of experimental and control groups, and the impact of confounding variables. Gain insights into how to apply John Stuart Mill's rules of inductive logic to experimental design.