How can a researcher ensure a study has internal validity?

How can a researcher ensure a study has internal validity?

• A. By randomly assigning participants and controlling extraneous variables.
• B. By increasing the sample size without controls.
• C. By using a convenience sample to gather data quickly.
• D. By employing subjective measures in analysis.

Answer: (A)

Internal validity refers to the degree to which a study can demonstrate a cause-and-effect relationship between the independent and dependent variables, free from the influence of confounding variables. Randomly assigning participants to different groups helps to eliminate selection bias and ensures that any differences observed between the groups can be attributed to the treatment rather than pre-existing differences among participants. Controlling extraneous variables further strengthens internal validity by minimizing their potential influence on the outcome of the study. By keeping these variables constant or equally distributed across groups, researchers can be more confident that the results are due to the manipulation of the independent variable rather than other factors. In contrast, merely increasing the sample size without proper controls does not enhance internal validity, as it does not address the potential confounding factors. Similarly, using a convenience sample may lead to a biased representation of the population, which is detrimental to drawing valid conclusions. Lastly, employing subjective measures can introduce biases and inconsistencies in data analysis, compromising the study’s internal validity. Therefore, the approach of random assignment and controlling for extraneous variables is essential for establishing strong internal validity in a research study.

Internal validity refers to the degree to which a study can demonstrate a cause-and-effect relationship between the independent and dependent variables, free from the influence of confounding variables. Randomly assigning participants to different groups helps to eliminate selection bias and ensures that any differences observed between the groups can be attributed to the treatment rather than pre-existing differences among participants.

Controlling extraneous variables further strengthens internal validity by minimizing their potential influence on the outcome of the study. By keeping these variables constant or equally distributed across groups, researchers can be more confident that the results are due to the manipulation of the independent variable rather than other factors.

In contrast, merely increasing the sample size without proper controls does not enhance internal validity, as it does not address the potential confounding factors. Similarly, using a convenience sample may lead to a biased representation of the population, which is detrimental to drawing valid conclusions. Lastly, employing subjective measures can introduce biases and inconsistencies in data analysis, compromising the study’s internal validity. Therefore, the approach of random assignment and controlling for extraneous variables is essential for establishing strong internal validity in a research study.