One concern in the early stages of study planning and design is the minimum sample size needed to provide statistically credible results. This minimum sample size is usually determined via the use of ...

Course TopicsPower analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required ...

Bruce Levin, Xun Chen, Is the One-Half Continuity Correction Used Once or Twice to Derive a Well-Known Approximate Sample Size Formula to Compare Two Independent Binomial Distributions?, The American ...

Prob chart. For both lines, the slope is greatest near 50%. Reading off the chart, the probability of winning with a poll of sample size 1100 is around 25% if the poll result was 49%, but improves ...