What is a significant limitation of the research design involving a single-group pretest-posttest study on language intervention?

What is a significant limitation of the research design involving a single-group pretest-posttest study on language intervention?

• A. The use of a single-group pretest-posttest design
• B. The absence of a control group
• C. The inability to rule out other factors for improvement
• D. All of the above

Answer: (D)

In a single-group pretest-posttest study design, several significant limitations arise that impact the reliability and validity of the findings related to language intervention. First, the use of this design inherently lacks a control group. A control group is essential in experimental research as it provides a baseline for comparing the effects of the intervention. Without a control group, researchers cannot definitively attribute observed changes in language skills solely to the intervention, as there is no comparison to measure these effects against. Second, one of the major limitations is the inability to rule out extraneous factors that could influence the outcomes. Improvements in language skills could result from various uncontrolled variables, such as maturation, environmental changes, or concurrent therapies, rather than the intervention itself. This lack of control over external influences compromises the study's ability to infer causation. These two points highlight the shortcomings of the research design, emphasizing that the findings may not accurately reflect the effectiveness of the language intervention. Consequently, all the mentioned limitations collectively emphasize the challenges associated with single-group pretest-posttest studies.

In a single-group pretest-posttest study design, several significant limitations arise that impact the reliability and validity of the findings related to language intervention.

First, the use of this design inherently lacks a control group. A control group is essential in experimental research as it provides a baseline for comparing the effects of the intervention. Without a control group, researchers cannot definitively attribute observed changes in language skills solely to the intervention, as there is no comparison to measure these effects against.

Second, one of the major limitations is the inability to rule out extraneous factors that could influence the outcomes. Improvements in language skills could result from various uncontrolled variables, such as maturation, environmental changes, or concurrent therapies, rather than the intervention itself. This lack of control over external influences compromises the study's ability to infer causation.

These two points highlight the shortcomings of the research design, emphasizing that the findings may not accurately reflect the effectiveness of the language intervention. Consequently, all the mentioned limitations collectively emphasize the challenges associated with single-group pretest-posttest studies.