When Should One Run a Crossover Design and Why?

• Activity Number: 620
• Type: Invited
• Date/Time: Thursday, August 7, 2014 : 10:30 AM to 12:20 PM
• Sponsor: Memorial
• Author(s): Sam Hedayat*+ and Wei Zheng
• Companies: University of Illinois at Chicago and Indiana University-Purdue University Indianapolis
• Keywords: Repeated measure Design ; Self Control Design ; Crossover Design ; Approximate Design

Abstract

Crossover designs is a special class of repeated measurements designs which have been utilized in many scientific studies including pharmaceutical ,medical, biological, and marketing. In these designs there will be more observations than experimental units. Repeated observations are made on each experimental unit in time, space, or both. By its nature any such design is very complicated to design and analyze he associated data. In this talk we shall review some outstanding statistical and mathematical issues related to these designs and discuss when one should and should not run such experiments. Approximate design theory simplifies the problem of searching for optimal designs by utilizing the tools from calculus. The approach has been applied to crossover designs since the 80's with the major breakthrough by Kushner (1997). However, the major transition from the traditional combinatory tools to this new approach did not occur until recently. This talk will summarize recent updates on new developments in this approach by visiting various models along with theorems and examples of optimal designs. Some insights regarding the symmetrization idea will be provided. Main challenges for