Discuss the similarities and differences between random sampling vs random assignment as well as the research problems they are used to solve
The Correct Answer and Explanation is:
Correct Answer:
Similarities:
- Both involve the use of random procedures to reduce bias.
- Both aim to ensure that results are as accurate and generalizable as possible.
- Both are used in research to improve the validity of the findings.
Differences:
- Random sampling is used to select participants from a larger population to be included in a study.
- Random assignment is used to place participants into different groups within the study, such as treatment and control groups.
Research problems they address:
- Random sampling addresses the problem of external validity, helping ensure that the sample represents the broader population.
- Random assignment addresses the problem of internal validity, helping ensure that differences in outcomes between groups are due to the intervention and not other variables.
Explanation
Random sampling and random assignment are both important methods used in research to reduce bias and strengthen the credibility of the findings. Although they are often confused, they serve different purposes and are applied at different stages of a study.
Random sampling is the process of selecting a group of participants from a larger population in such a way that each individual has an equal chance of being chosen. This method is mainly used in survey research, population studies, or any research that requires generalization to a larger group. The goal of random sampling is to create a sample that accurately reflects the characteristics of the population, which enhances external validity — the extent to which the study’s results can be generalized beyond the sample.
Random assignment, in contrast, occurs after participants have been selected for the study. It involves randomly placing those participants into different groups, such as experimental or control groups. This technique is typically used in experimental research and aims to ensure that each group is equivalent at the start of the experiment. The purpose is to isolate the effect of the independent variable by minimizing the impact of confounding variables. This increases internal validity, or the degree to which observed effects can be attributed to the intervention rather than other factors.
In summary, random sampling helps researchers draw unbiased samples from a population, while random assignment helps ensure that any differences in outcomes can be attributed to the treatment being studied. Both are essential tools for conducting reliable and meaningful research.
