About This Chapter
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- Students who have fallen behind in understanding threats to internal validity and the methods used to mitigate their effects
- Students who struggle with learning disabilities or learning differences, including autism and ADHD
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How it works:
- Find videos in our course that cover what you need to learn or review.
- Press play and watch the video lesson.
- Refer to the video transcripts to reinforce your learning.
- Test your understanding of each lesson with short quizzes.
- Verify you're ready by completing the Internal Validity in Research chapter exam.
Why it works:
- Study Efficiently: Skip what you know, review what you don't.
- Retain What You Learn: Engaging animations and real-life examples make topics easy to grasp.
- Be Ready on Test Day: Use the Internal Validity in Research chapter exam to be prepared.
- Get Extra Support: Ask our subject-matter experts any internal validity question. They're here to help!
- Study With Flexibility: Watch videos on any web-ready device.
Students will review:
This chapter helps students review the concepts in an internal validity unit of a standard research methods in psychology course. Topics covered include:
- Extraneous and confounding variables
- Physical variables that affect internal validity
- Researcher and participant variables that affect internal validity
- Instrumentation and subject mortality
- Statistical regression and testing effects
- Subject selection and maturation
- Single blind, double blind and placebo control methods
1. What is Internal Validity in Research? - Definition & Examples
The purpose of most research is to show that one variable causes changes in another variable. But, what happens when other variables come into play? In this lesson, we'll explore the definition, importance and threats to internal validity.
2. Extraneous & Confounding Variables: Differences & Examples
What happens when something other than your independent variable is influencing the outcome of your study? In this lesson, we'll look at two types of variables that can affect an experiment: extraneous and confounding variables.
3. Physical Variables that Affect Internal Validity
How might a researcher accidentally mess up the results of his or her study? In this lesson, we'll look at one type of extraneous variable that can change experimental results - physical or situational variables.
4. Researcher Variables that Affect Internal Validity
Scientists want only the independent variable to affect the outcome of their studies, but sometimes it is the things they do themselves that change the outcome. We'll look at three common researcher-related variables: researcher bias, selection bias, and researcher personality in this lesson.
5. Participant Variables that Affect Internal Validity
Sometimes, participants in an experiment can change the outcome. In this lesson, we'll look at some of the extraneous variables caused by participants: self-selection bias, demand characteristics, and good-subject bias.
6. Threats to Internal Validity I: History, Instrumentation & Subject Mortality
In research, there are many things besides the independent variable that can affect the dependent variable. In this lesson, we'll look at three of those things - history, mortality, and instrumentation - and what they mean to research.
7. Threats to Internal Validity II: Statistical Regression & Testing
If you're doing research, how do you know if one thing causes another? In this lesson, we'll look at some common threats to the internal validity of experiments, including testing effects and regression to the mean.
8. Threats to Internal Validity III: Selection, Maturation & Selection Interaction
A major goal of research is to prove that one thing causes another thing. But there are some hurdles to being able to say that. In this lesson, we'll look at three threats to internal validity: selection, maturation, and selection interaction.
9. Controlling for Extraneous Variables: Single Blind, Double Blind & Placebo Methods
Sometimes researchers are confronted with extraneous factors that affect the outcome of their studies. In this lesson, we'll look at ways to control for these extraneous variables, including single-blind and double-blind studies and placebos.
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Other chapters within the Research Methods in Psychology: Help and Review course
- Introduction to Research Methods: Help and Review
- Principles of Ethical Research: Help and Review
- Setting Up the Research Study: Help and Review
- Data Collection Techniques in Psychology: Help and Review
- Nonexperimental Research: Help and Review
- Qualitative Research Methods and Design: Help and Review
- Quasi-Experimental Research: Help and Review
- Sampling and Generalization: Help and Review
- Measurement in Research: Help and Review
- External Validity: Help and Review
- Experimental Design: Help and Review
- Descriptive Statistics in Psychology: Help and Review
- Inferential Statistics in Psychology: Help and Review
- Evaluating Research Findings: Help and Review
- Ethics in Counselor-Supervisor Relationships