experimental quantitative research

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Getting Started

As a social researcher, you may be interested in conducting an experimental study. This design is used when a researcher identifies a problem and is interested in implementing an intervention to see if the technique causes a change in the participants’ behaviors. Unlike correlation research, which only identifies a relationship between variables, experimental research allows the researcher to manipulate variables to identify causation. For example, a researcher may be interested in exploring the effects of cognitive-behavioral therapy on anxiety.

Upon successful completion of this assignment, you will be able to:

  • Access the library for empirical studies.
  • Demonstrate in writing the elements of each research methodology.

Resources

  • Textbook: Writing Empirical Research Reports
  • File: Experimental Research Example.pdf
  • File: Research Methods Cheat Sheet.pdf
  • Website: IWU Library Services
  • Website: Citation Machine

Background Information

Experimental research falls into three categories: pre-experimental, quasi-experimental, and true experimental. Within each category are various approaches to implement an experimental study. Depending on the problem statement, resources, and time, the researcher will choose the most appropriate design.

Types of Pre-/True/Quasi-Experimental Designs

Pre Experimental Design Approach
True Experimental Design Approach
Quasi Experimental Design Approach

Purpose:

Experimental research serves to help the researcher implement an intervention, manipulate variables, and determine cause and effect. In the experimental study that aims to identify the relationship between cognitive-behavioral theory and anxiety, the intervention is cognitive-behavioral theory, while anxiety is the dependent variable. For this study, a true experimental, pre-test/post-test control group design approach would be effective.

Sampling:

Sampling methods can be probability and non-probability. If the participants in the study all must have a diagnosis of anxiety, a researcher would use a criterion sampling method.

However, in many situations, a probability sampling method, such as a stratified random sample, could be used. For example, the researcher may be interested in understanding the effects of cognitive behavioral therapy on anxiety among college students. The researcher could stratify the students into three groups: freshmen, sophomores, and juniors. Obtaining a sample of 30 participants (10 from each group), five from each group could be randomly placed into the intervention group or the control group, giving the researcher 15 participants in the intervention group and 15 participants in the control group.

Data Collection:

To collect the data, first the researcher would give all participants a pre-test to assess their levels of anxiety. For the next 10 weeks, the intervention group would receive the cognitive behavioral therapy. After 10 weeks, the control group and intervention group would receive the post-test.

Data Analysis:

To analyze the data, the researcher would use a statistic. To determine the statistical test, the researcher must answer three questions:

  1. What is the level of measurement of the dependent variable?
  2. How many samples are there?
  3. Are the samples independent of or dependent on each other?

The level of measurement of the dependent variable (anxiety) is scaled data. This is because we can measure anxiety in units. There are four groups that are independent of each other; therefore, the researcher will use the statistical test called an Analysis of Variance (ANOVA). ANOVA is used to measure the differences in means among three or more groups.

However, for this particular study, the researcher could take the analysis a step further. Although ANOVA is acceptable for understanding the differences in the means among the groups, extraneous variables may affect the results. Therefore an Analysis of Covariance (ANCOVA) could be used. ANCOVA is a combination of ANOVA and regression analysis (found in correlation data analysis). The purpose of ANCOVA is to control for confounding factors that may be influencing the results of the study.

To use ANCOVA, three factors must be met:

  1. The independent variable must be nominal data.
  2. The dependent variable must be interval data.
  3. The covariant must be interval data.

In this study:

  1. The independent variable (cognitive behavioral therapy) is nominal data.
  2. The dependent variable (anxiety) is interval data.
  3. The covariant (the pre-test score) is interval data.

Instructions

  1. Review the rubric to make sure you understand the criteria for earning your grade.
  2. Read Chapter 10 in your textbook Writing Empirical Research Reports.
  3. Review the Experimental Research Example.pdf file.
  4. Review the Research Methods Cheat Sheet.pdf file.
  5. Visit IWU Library Services:
    1. Go to the IWU library databases and locate a peer-reviewed experimental research study in social work.
  6. Identify in writing the elements of the qualitative research study, which include:
    1. The problem of the study
    2. The sampling methods used
    3. The data collection methods used
    4. The data analysis used
    5. A summary of the study results
  7. Be sure to follow APA formatting, to include a cover page and a reference page.
  8. Your assignment should be a minimum of one page, not including the cover page and reference page.