1. What is the purpose of the study?

The purpose of the study to reveal effective approaches to teaching ratio and proportion in grate 6 and 7. The researchers conducted the experiment that aimed at the revelation of the effectiveness of their approach based on the use of the detailed analysis of complexity of ratio problems, involving precise guidelines and a specific computer environment.

2. What type of research design is used (must use classification of designs in chapter 11)?

The type of the research design was descriptive. The researchers conducted the experiment and described it in details focusing on the participants of the experiment, revealing details how and when the experiment was conducted and what outcomes of the experiment were.

3. How does the research design control for the following threats to internal validity:

a. Selection

The selection of subjects of the research was grounded on the problem of the study and its goals. Therefore, students of grade 6 and 7 were selected to participate in the study randomly. The subjects were divided into three groups: partial-experiment group, full-experiment group and control group. All participants were approximately of the same age, similar education level and cognitive development. In such a way, the researchers reached a relatively high level of objectivity and validity of the study.

b. Maturation

The maturation of the study is quite reliable although the further study may be needed to test the validity of the findings of the current study because groups involved in the experiment were relatively small. Therefore, there is a risk of error and inaccuracy in findings of the researchers. This means that the maturation level of the study may not be considered absolutely valid.

c. Mortality

The mortality is not a credible concern in this study because the study focuses on the analysis of the problem of increasing the effectiveness of teaching ratio and proportion that means that the experiment focuses on the assessment of the effectiveness of different approaches that makes the application of mortality threat to this experiment irrelevant because there was no such threat in the study.

d. Regression

The regression was taken into consideration by the researchers for they conducted the detailed research before and after the study focusing on the analysis of skills of students in solving ratio and proportion problems.

e. Testing

The study involve pre-testing and post-testing that minimizes the threat of invalid testing because the researchers obtained the information on the level of the development of students before and after the experiment.

f. Instrumentation

The instrumentation was valid because it involved conventional instruments and new ones developed by researchers to test in the course of the study and to test their effectiveness.

g. History

The history of the study is valid because researchers relied on the past studies and findings and complemented them by their experiment.

4. What are findings of the study (be brief)?

The findings of the study reveal the fact that the use of the detailed analysis of complexity of ratio problems, involving precise guidelines and a specific computer environment is helpful in teaching students of grade 6 and 7 to solve ratio and proportion problems.

5. Is the study internally valid? Why or why not?

The study is internally valid because it involved pre- and after-testing to verify the effect of the experiment, while all subjects were in similar conditions. In addition, the researchers used control group to test the validity and reliability of the study.

6. Is the study externally valid? Why or why not?

The external validity of the study is not absolute and may need further enhancement and study because the study involved a relatively small group of students.


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