What is the impact on the size of the needed sample of changing from .01 confidence in meeting specified requirements to .05 confidence?

Changing from a 0.01 confidence level to a 0.05 confidence level typically reduces the required sample size. This is because a higher confidence level (0.01) indicates a stricter criterion for statistical significance, necessitating a larger sample to achieve the same power. Conversely, a 0.05 confidence level allows for a greater margin of error, thereby requiring fewer observations to detect an effect or meet specified requirements. As a result, the sample size can often be reduced when accepting a higher alpha level.