Two Group Experimental Design PP1234

Amy Binch

11 Mar 201802:53

Summary

TLDRThis script delves into the two-group experimental design, a method to test the impact of a variable on two distinct groups: a control and a treatment group. It explains two fundamental designs: the pretest-posttest control group design, where subjects are randomly assigned and knowledge is measured before and after an educational intervention, and the post-test-only control group design, which omits the pretest. Both aim to quantify the effect of the intervention on knowledge, such as an educational video on influenza, by comparing post-test scores.

Takeaways

🔬 Two group experimental design is a method used to test the effects of a variable on two different groups: a control group and a treatment group.
📚 The purpose of this design is to measure the effect of an independent variable that can be manipulated, such as an educational intervention.
🎥 An example given is an educational video on influenza to test its impact on knowledge about the subject.
🔄 There are two basic designs within two group experiments: pretest-post-test control group design and post-test only control group design.
🔄💉 In the pretest-post-test control group design, subjects are randomly assigned to either group and given a pretest before the treatment.
📉 The treatment group receives the educational intervention, and then both groups are retested to measure changes in the dependent variable.
⚖️ The effect of the treatment is determined by comparing the difference in post-test and pretest scores between the control and treatment groups.
📊 The post-test only control group design omits the pretest, focusing solely on the post-test results to evaluate the treatment's effect.
📈 The effectiveness of the educational session is calculated by subtracting the control group's post-test scores from the treatment group's scores.
📝 Random assignment is crucial in these designs to ensure that the groups are comparable and the treatment effect can be accurately measured.
🔑 The dependent variable of interest in the script's example is knowledge about influenza, which is measured before and after the educational intervention.

Q & A

What is a two-group experimental design?
-A two-group experimental design is a simple and true experimental design that tests the effects of a variable on two different groups: a control group and a treatment group. It measures the effect of an independent variable that can be manipulated as a treatment.
What is the purpose of an educational video on influenza in this experimental design?
-The educational video on influenza serves as the treatment in the experimental design, aiming to improve the participants' knowledge on influenza.
What are the two basic designs within two-group experiments mentioned in the script?
-The two basic designs within two-group experiments are the pretest-post-test control group design and the post-test-only control group design.
How are subjects assigned in the pretest-post-test control group design?
-In the pretest-post-test control group design, subjects are randomly assigned to either the control group or the treatment group.
What is measured in the pretest and post-test in the pretest-post-test control group design?
-In the pretest-post-test control group design, the dependent variable of interest, in this case, knowledge, is measured before and after the treatment.
What is the treatment given to the treatment group in this experimental design?
-The treatment given to the treatment group is the educational video on influenza.
How does the pretest-post-test design measure the effect of the treatment?
-The pretest-post-test design measures the effect of the treatment by comparing the difference in post-test and pretest scores between the control and treatment groups.
What is the main difference between the pretest-post-test control group design and the post-test-only control group design?
-The main difference is that the pretest-post-test control group design includes a pretest, while the post-test-only control group design does not.
How is the effect of the treatment calculated in the post-test-only control group design?
-In the post-test-only control group design, the effect of the treatment is calculated by subtracting the post-test results of the control group from the post-test results of the treatment group.
What does the comparison of post-test scores between the control and treatment groups indicate?
-The comparison of post-test scores between the control and treatment groups indicates the effect of the educational session on influenza knowledge.
Why is random assignment important in experimental designs?
-Random assignment is important in experimental designs to ensure that the groups are similar before the treatment is applied, thus reducing the likelihood of bias and increasing the validity of the results.

Outlines

00:00

🔬 Introduction to Two-Group Experimental Design

The paragraph introduces the concept of a two-group experimental design, which is a method used to test the effects of a variable on two distinct groups: a control group and a treatment group. The paragraph explains the purpose of this design, which is to measure the impact of an independent variable, such as an educational video on influenza, on a dependent variable, such as knowledge about influenza. The paragraph also distinguishes between two types of two-group experimental designs: the pretest-post-test control group design and the post-test-only control group design, providing a brief overview of how each design operates and the significance of their respective outcomes.

Mindmap

Keywords

💡Two Group Experimental Design

This refers to a research methodology where two distinct groups are compared: a control group and a treatment group. The design is used to evaluate the impact of an independent variable on a dependent variable. In the context of the video, it is used to assess the effectiveness of an educational video on influenza knowledge. The script explains that this design can take two forms: pretest-posttest control group design and post-test only control group design.

💡Control Group

A control group is a standard part of an experiment where the subjects do not receive the experimental treatment. It serves as a baseline to compare against the treatment group to measure the effect of the independent variable. In the script, the control group is used to understand the natural knowledge level of the subjects before and after the educational intervention.

💡Treatment Group

The treatment group is the counterpart to the control group in an experiment, where subjects are exposed to the independent variable, such as the educational video on influenza in the video's example. The treatment group's performance is compared against the control group to determine the effect of the intervention.

💡Independent Variable

The independent variable is the element that researchers manipulate in an experiment to observe its effect on the dependent variable. In the script, the independent variable is the educational video, which is used to influence the subjects' knowledge on influenza.

💡Dependent Variable

The dependent variable is the outcome that researchers measure in an experiment to see if it changes as a result of the independent variable. In the video, the dependent variable is the knowledge on influenza, which is measured before and after the treatment.

💡Pretest-Posttest Control Group Design

This design involves administering a test to measure the dependent variable before and after the treatment. It allows for the assessment of the treatment's impact by comparing the scores from the pretest and posttest within each group. The script describes this design as a method to measure the effect of the educational video on knowledge about influenza.

💡Post-Test Only Control Group Design

This design is similar to the pretest-posttest control group design, but it omits the pretest. It measures the dependent variable only after the treatment has been administered. The script explains that the effect of this design is determined by subtracting the post-test results of the control group from those of the treatment group.

💡Random Assignment

Random assignment is the process of assigning subjects to groups in an experiment without bias, to ensure that each subject has an equal chance of being in either the control or treatment group. The script mentions this as a method to ensure fairness in the experimental design.

💡Effect Size

Effect size is a measure of the strength of the relationship between the independent and dependent variables. In the script, it is calculated by comparing the difference in pretest and posttest scores between the treatment and control groups, providing insight into the impact of the educational video.

💡Educational Video

In the context of the video, the educational video serves as the treatment that is hypothesized to improve knowledge on influenza. It is the intervention that the experimental design is testing for its effectiveness.

💡Influenza Knowledge

Influenza knowledge is the specific area of knowledge that the educational video is intended to improve. It is the dependent variable in the experiment, and the script discusses how it is measured and compared between the control and treatment groups.

Highlights

Two group experimental design is a simple and true experimental design that tests the effects of a variable on two different groups - a control group and a treatment group.

The design measures the effect of an independent variable that can be manipulated as a treatment, such as an educational video on influenza.

There are two basic designs within two group experiments: the pretest post-test control group design and the post-test only control group design.

In the pretest post-test control group design, subjects are randomly assigned to either the control or treatment group and given a pretest to measure their knowledge.

The treatment group receives the educational video on influenza after the pretest.

Both the control and treatment groups are retested after the treatment to measure the effect on their knowledge.

The effect of the pretest post-test design is measured by the difference in post-test and pretest scores between each group.

The post-test only control group design is similar to the pretest post-test design, but without a pretest.

The effect of the post-test only design is determined by subtracting the post-test results of the control group from the treatment group.

The purpose of the educational video on influenza is to improve knowledge on the subject.

Random assignment of subjects to groups helps ensure the validity of the experimental design.

The pretest serves as a baseline measure of knowledge before the treatment is applied.

The post-test measures any changes in knowledge after the treatment has been administered.

Comparing post-test and pretest scores allows for the evaluation of the treatment's effectiveness.

The difference in scores between the control and treatment groups indicates the impact of the educational video.

The post-test only design simplifies the experimental process by eliminating the pretest.

The effectiveness of the educational video is determined by comparing the post-test scores of both groups.

The two group experimental design provides a clear method for evaluating the impact of educational interventions on knowledge acquisition.