Estimating proportions by group retesting with unequal group sizes at each stage

Unequal group sizes in randomised trials: guarding against guessing.

We cringe at the pervasive notion that a randomised trial needs to yield equal sample sizes in the comparison groups. Unfortunately, that conceptual misunderstanding can lead to bias by investigators who force equality, especially if by non-scientific means. In simple, unrestricted, randomised trials (analogous to repeated coin-tossing), the sizes of groups should indicate random variation. In ...

An Adaptive Group-testing Procedure for Estimating Proportions

Group-testing procedures begin by testing units in groups or batches rather than one at a time. This scheme benefits from the possibility that a single measurement/response may simultaneously indicate the satisfactory state of several individual units. Indeed, the savings afforded by group-testing procedures can be substantial, provided a good choice of the group size is made. Unfortunately, ca...

Unequal group variances in microarray data analyses

MOTIVATION In searching for differentially expressed (DE) genes in microarray data, we often observe a fraction of the genes to have unequal variability between groups. This is not an issue in large samples, where a valid test exists that uses individual variances separately. The problem arises in the small-sample setting, where the approximately valid Welch test lacks sensitivity, while the mo...

Centralized Caching with Unequal Cache Sizes

We address centralized caching problem with unequal cache sizes. We consider a system with a server of files connected through a shared error-free link to a group of cacheenabled users where one subgroup has a larger cache size than the rest. We investigate caching schemes with uncoded cache placement which minimize the load of worst-case demands over the shared link. We propose a caching schem...

Environmental Curricula Development for Each Age Group