This text appears to be a lecture or tutorial on statistics in machine learning, specifically covering topics such as correlation analysis, permutation testing, and power calculations. Here's a summary of the main points:
1. **Simplicity is key**: The author emphasizes the importance of simplicity in statistical analyses, making it easier for readers and others to understand the results. 2. **Violations are okay**: Most statistical violations can be ignored without significant consequences, except for independence and outliers. 3. **Avoid exotic methods**: Using complex statistics that are not widely recognized or understood can lead to confusion and decreased accessibility of your work. 4. **Permutation testing is essential**: Permutation testing is a powerful tool for checking the validity of analytical results, especially when dealing with complex or hierarchical data. 5. **Power calculations are important**: Understanding power calculations can help you determine whether your experiment has enough statistical power to detect significant effects. 6. **Don't test too frequently**: While it may seem like collecting more data will always lead to stronger evidence, this is not necessarily the case. Repeated hypothesis testing with a strict threshold can be more effective than collecting a predetermined sample size and only testing once at p < 0.05. 7. **Consider mass-pooling strategies**: When working with hierarchical data, it may be necessary to pool data by response or use multilevel linear regression to account for the hierarchical structure. 8. **Be aware of confound artifacts**: Confounds can have significant impacts on results, especially when using techniques like z-scoring. It's essential to understand these potential artifacts and take steps to mitigate them.
Some key concepts and formulas mentioned in the text include:
* Spearman rank correlation: A non-parametric measure of correlation that is more robust than Pearson's r. * Permutation testing: A statistical method for checking the validity of analytical results by randomly shuffling the data. * Power calculations: The probability of detecting a statistically significant effect, given the hypothesized effect size, sample size, and significance threshold. * Statistical power: A measure of the ability to detect an effect, with higher values indicating greater power.
Overall, this text provides a comprehensive overview of statistical concepts and techniques in machine learning, with a focus on simplicity, power, and permutation testing.