About This Chapter
Experimental Design - Chapter Summary and Learning Objectives
In this chapter, you'll learn about experimental design, one of the most important factors in scientific research. Instructors explain key aspects of experiment design, including how to achieve random assignment, what purpose control groups serve and why variables matter. This chapter is designed to teach you about topics including:
- Between-subjects designs
- The importance of random assignments
- Group designs, including two-group and matched group design
- Types of within-subjects designs
|Between-Subjects Designs: Definition and Examples||Define and discuss this type of design that tests two or more groups at the same time.|
|Random Assignment in Research: Definition and Importance||Define and discuss random assignment, its importance and how it is accomplished.|
|What is a Control Group? - Definition and Use in Research||Define and discuss control groups and the use of experimental groups and control groups in research designs.|
|Two-Group Experimental Designs: Definition and Examples||Define and discuss the basic two-group experimental design in psychology research.|
|Matched Group Design: Definition and Examples||Define and discuss matched group design and how it can test for extraneous variables.|
|Multiple Group Design: Definition and Examples||Define and discuss multiple group design and the observation of an independent variable.|
|What is Factorial Design? - Definition and Examples||Define and discuss factorial design and how researchers can study more than one independent variable at a time.|
|Factorial Design Variations||Explain the different factorial designs and how researchers would use them.|
|Within-Subjects Designs: Definition, Types and Examples||Define and discuss within-subjects designs, including one independent variable, multiple independent variables and mixed designs.|
|Carryover Effects and How They Can Be Controlled Through Counterbalancing||Define and discuss carryover effects and how to control them.|
|Small n Designs: ABA and Multiple-Baseline Designs||Explain small n designs and discuss ABA and multiple-baseline designs.|
1. Between-Subjects Designs: Definition & Examples
Many times in research, a psychologist wants to look at two or more groups to see which condition works best. In this lesson, we'll look at some of the strengths and weaknesses of the between-subjects design and how to form equivalent groups.
2. Random Assignment in Research: Definition and Importance
In order to get the most accurate results, researchers must choose and assign their subjects in a random manner. In this lesson, we'll look at random assignment, random selection, and why they are important.
3. What is a Control Group? - Definition and Use in Research
In research, many times a condition is compared to a group that doesn't receive treatment. In this lesson, we'll look at what a control group is and why it is important.
4. Two-Group Experimental Designs: Definition & Examples
How does a researcher know if their treatment has an effect or not? In this lesson, we'll look at two-group experimental designs, contrast control and treatment groups, and examine random assignment and matched groups.
5. Matched-Group Design: Definition & Examples
Choosing how to divide subjects into groups is a major part of experimental design. In this lesson, we'll look at a type of non-random assignment, matched-group design, and its strengths and limitations.
6. Multiple Group Design: Definition & Examples
What happens when a researcher has many groups in their study? In this lesson, we'll look closer at multiple-group design, including multiple-group design with independent groups and multiple-group design with correlated groups.
7. What is Factorial Design? - Definition & Example
The simplest studies involve one independent and one dependent variable. But what happens when a researcher wants to study more than one independent variable? In this lesson, we'll look closer at factorial design in research.
8. Factorial Design Variations
When a study has more than one factor, it is called a factorial design. In this lesson, we'll go through different variations on factorial designs, including those involving factor levels and those involving between- or within-groups measurement.
9. Interactions in Factorial Design
When a study has a factorial design, the two independent variables can interact with each other to affect the dependent variable. In this lesson, we'll look at what interactions are, what they look like, and what a crossover interaction is.
10. Main Effects in Factorial Design
When you have more than one independent variable, sometimes you want to look at how they work independent of each other. In this lesson, we'll examine main effects in factorial design and how they differ from interactions.
11. Multivariate Experimental Design
Most research studies only have one dependent variable. But what if a researcher wants to study more than one dependent variable? In this lesson, we'll look at multivariate research designs and how they differ from factorial designs.
12. Within-Subject Designs: Definition, Types & Examples
Sometimes a researcher wants to look at how each subject does at different points during a study. In this lesson, we'll look at some of the strengths and weaknesses of a within-subjects design and how to counterbalance subjects for a stronger study.
13. Carryover Effects & How They Can Be Controlled Through Counterbalancing
Within-subjects research has a lot of advantages, but one disadvantage is the possibility of carryover effects. In this lesson, we'll examine carryover effects and how they can be controlled through a counterbalanced design.
14. Small n Designs: ABA & Multiple-Baseline Designs
When planning a study, the size of the sample can influence the results of the study. To get around this, some researchers choose a research design specifically meant for small sample sizes. In this lesson, we'll look at some small 'n' designs.
15. Advantages & Disadvantages of Various Experimental Designs
There are many different options for researchers when deciding how to run a study. In this lesson, we'll look at some of the advantages and disadvantages of some common experimental designs.
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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
- External Validity
- Descriptive Statistics in Psychology
- Inferential Statistics in Psychology
- Evaluating Research Findings
- Studying for Psychology 105