The choice of the statistical tests that will be used in a study is made:

• A. Before a study is done
• B. At the beginning of a study
• C. Midway during the study
• D. At the end of the study

Answer: (A)

Planning the statistical analysis before any data are collected is essential. Deciding which tests to use during the design phase ensures the methods match the study design and hypotheses, and it sets clear rules for how results will be evaluated. This upfront plan helps prevent bias and data-dredging, where different tests are tried after seeing the data to achieve a significant finding. It also guides sample size decisions and analysis rules (such as how missing data will be handled), contributing to credible, reproducible results. Therefore, the appropriate time to choose the statistical tests is before the study is done.