Data preprocessing and cleaning

You can provide data preprocessing and cleaning for complex datasets, as well as perform related statistical analysis and interpretation. What steps should be included in the process of data preprocessing and cleaning? How should outliers be handled, how should missing data be handled, and how should variables be transformed? What factors should be considered when selecting appropriate statistical models or tests? How should statistical model or test outputs be interpreted, and how should significance and effect size be determined in the results? Additionally, how should the reliability of model or test results be evaluated?