Conjoint analysis studies typically utilize orthogonal fractional factorial experimental designs to construct a set of hypothetical stimuli. Occasionally, these designs include environmentally correlated attributes that can lead to stimulus profiles that are not representative of the subject’s environment. To date, no one has proposed a remedy well-grounded in statistical theory. This note pres...

This article addresses the varied possibilities for following a two-level fractional factorial with another fractional factorial half the size of the original experiment. While follow-up fractions of the same size as an original experiment are common practice, in many situations a smaller follow-up experiment will suffice. Peter John coined the term “semifolding” to describe using half of a fol...

Discrete choice experiments (DCEs) are increasingly used for studying and quantifying subjects preferences in a wide variety of healthcare applications. They provide a rich source of data to assess real-life decision-making processes, which involve trade-offs between desirable characteristics pertaining to health and healthcare and identification of key attributes affecting healthcare. The choi...

In this paper we create the connection of wrap-around-discrepancy and aberration of regular fractional factorial designs with two and three levels. For any level we give the connection of uniformity and orthogonality only for complete design.

Recent work on multistratum fractional factorial designs is set in a general and unified framework, and a criterion for selecting multistratum fractional factorial designs that takes stratum variances into account is proposed. Application of the general theory is illustrated on designs of experiments with multiple processing stages, including split-lot designs, blocked strip-plot designs, and p...

Many disorders require multi-component treatments given sequentially in time to achieve and maintain good outcomes. The development of these adaptive treatment strategies is challenging due to the large number of components and sequencing of components. We propose the use of screening experiments in which scientists screen out inactive components. Unfortunately when the goal is to construct ada...