Final answer:
To increase power and reduce variability of raw scores, you can increase the sample size, control lurking variables, and use standardized procedures for data collection.
Step-by-step explanation:
One way to increase power in statistical testing is to minimize the variability of the raw scores. This can be done through several methods. Increasing the sample size often helps to reduce variability and therefore enhance the power of the test. When you have more data points, the mean is likely to be a more accurate estimate of the population parameter, which reduces the impact of outliers. Additionally, controlling for or removing lurking variables can decrease variability. These are variables that might influence the outcome of the study and introduce noise into the data. By controlling for these variables through study design, the true effect can be more accurately measured. Another strategy is to use standardized procedures for data collection, which ensures consistency across measurements and reduces the chances of variability due to procedural differences.