PASS is a computer program for estimating sample size or determining the power of a statistical test or confidence interval. NCSS LLC is the company that produces PASS. NCSS LLC also produces NCSS (for statistical analysis) and GESS (Gene Expression Statistical System for Microarray data).

PASS includes over 150 documented sample size and power procedures.

Major statistical topics in PASS

• Means - 1 or 2 Groups
• Means - Correlated or Paired
• Means - Cross-Over Designs
• Means - Many (ANOVA)
• Survival Analysis
• Variances
• ROC Curves
• Equivalence
• Normality Tests
• Confidence Intervals
• Proportions - 1 or 2 Groups
• Proportions - Correlated or Paired
• Proportion - Many Groups
• Mixed Models
• Regression/Correlation
• Non-Inferiority
• Group Sequential Tests
• Design of Experiments