About This Chapter
External Validity - Chapter Summary and Learning Objectives
With the lessons in this chapter, you'll gain an understanding of external validity and how it is important to psychology research and experiments. The requirements for external validity are explored, and you'll learn about the factors that can threaten external validity. Another lesson describes methods of increasing external validity. By the end of this chapter, you will know more about the following:
- Characteristics of external validity
- Internal validity and why it is necessary for external validity
- Threats to external validity, such as multiple-treatment interference
- How to increase external validity, including aggregation and field experiments
- Generalization and external validity
|What is External Validity in Research? - Definition and Examples||Define and discuss external validity, or how much the results of an experiment can be generalized.|
|Requirements of External Validity: Internal Validity and Replication||Discuss internal validity and replication as basic requirements for external validity.|
|Generalization and External Validity||Explain external validity issues such as generalization across subjects, generalization from procedures to concepts and generalizing beyond the lab.|
|Threats to External Validity I: Sample Characteristics, Stimulus Characteristics and Experimental Arrangements||Explain how sample characteristics, stimulus characteristics and reactivity of experimental arrangements affect external validity.|
|Threats to External Validity II: Novelty Effects, Test Sensitization and Measurement Timing||Explain how novelty effects, test sensitization and timing of measurement threaten external validity.|
|Methods for Increasing External Validity||Explain how aggregation, multivariate designs, nonreactive measures, field experiments and natural observation can increase external validity.|
1. What is External Validity in Research? - Definition & Examples
The purpose of research is to say something about the real world. But how can a researcher generalize results to the world at large? In this lesson, we'll answer that question as we learn about external validity.
2. Requirements of External Validity: Internal Validity & Replication
In order to generalize results from studies to the real world, there are a couple of things that are required. In this lesson, we look at the requirements for external validity: replication and internal validity.
3. Generalization & External Validity
The point of research is to be able to generalize findings to the world at large. In this lesson, we'll look at three types of generalizing that make up external validity: across subjects, from procedures to constructs, and beyond the lab.
4. Threats to External Validity: Sample Characteristics, Stimulus Characteristics & Experimental Arrangements
The goal of research is to generalize the results, but there are several things that can get in the way. This lesson examines three threats to external validity: sample characteristics, stimulus characteristics, and multiple-treatment interference.
5. How Novelty Effects, Test Sensitization & Measurement Timing Can Threaten External Validity
The purpose of research is to find things out about the world at large. But there are several things that can get in the way of external validity. In this lesson, we'll examine novelty effects, test sensitization, and measurement timing.
6. Reactivity of Experimental Arrangements & Assessment: Threats to External Validity
The goal of research is to say something about what happens in the real world. But what happens if subjects react to the experimental conditions? In this lesson, we'll look at two reactivity threats to external validity.
7. Methods for Increasing External Validity
External validity is a key component of research. In this lesson, we'll look at several different ways to increase external validity, including aggregation, nonreactive measures, and field research.
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Other chapters within the Psychology 105: Research Methods in Psychology course
- Introduction to Research Methods
- Principles of Ethical Research
- Setting Up the Research Study
- Data Collection Techniques in Psychology
- Nonexperimental Research
- Qualitative Research Methods and Design
- Quasi-Experimental Research
- Sampling and Generalization
- Measurement in Research
- Internal Validity in Research
- Experimental Design
- Descriptive Statistics in Psychology
- Inferential Statistics in Psychology
- Evaluating Research Findings
- Studying for Psychology 105