What is the difference between random sampling and random assignment? Random sampling is used to increase external validity; random assignment is used to increase internal validity. Random sampling is used to increase internal validity; random assignment is used to increase external validity. Random sampling is used to increase statistical validity; random assignment is used to increase face validity. Random sampling and random assignment are the same thing.
The Correct Answer and Explanation is:
Correct Answer: Random sampling is used to increase external validity; random assignment is used to increase internal validity.
Explanation:
In experimental design and research methodology, it is essential to distinguish between random sampling and random assignment, as they serve different purposes and affect different types of validity in a study.
Random sampling refers to the process of selecting a representative group of individuals from a larger population. This technique ensures that every individual in the population has an equal chance of being chosen for the study. The primary goal of random sampling is to enhance external validity, which is the extent to which the results of a study can be generalized to the broader population. By using a random sampling method, researchers reduce selection bias and increase the likelihood that the sample accurately reflects the diversity of the population.
On the other hand, random assignment is used after the sample has been selected. It involves randomly placing participants into different groups or conditions within the study, such as a treatment group and a control group. This process ensures that each participant has an equal chance of being assigned to any group. The key purpose of random assignment is to enhance internal validity, which refers to the degree to which the results of a study can be attributed to the variables being tested rather than other confounding variables. By randomly assigning participants, researchers control for potential biases and ensure that differences between groups are due to the experimental treatment rather than preexisting differences.
In summary, random sampling increases the generalizability of the study (external validity), while random assignment strengthens the cause-and-effect relationship by reducing confounding variables (internal validity). Understanding this distinction is crucial for designing robust and credible research studies.
