This article describes a sampling experiments based on Opinion-poll type data as an alternative to coin-tossing experiments for social science students.

This page calculates the expected number of deaths, the expected proportion of deaths at a given time, or the time at which a given proportion of deaths have occurred for a planned study. Users can...

This page calculates either estimates accrual or power for differences in survival times between two groups. The program allows for unequal sample size allocation between the two groups. The survival...

This page calculates either estimates of sample size or power for interaction tests. The program allows for unequal sample size allocation in the four cells defined by the two treatment groups and...

The dataset presented in this article comes from a South African study of growth of children. This data is a useful example of Simpson's paradox. Key Words: Categorical data; Comparing proportions.

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