PLACE: 319 Snedecor

SPEAKER:
Hegang Chen
Division of Biostatistics
University of Minnesota

TITLE:
Estimation Index of Fractional Factorial Designs
 

ABSTRACT:
Fractional factorial designs have a long history of successful use in scientific investigations.  Resolution (Box and Hunter (1961)) and its refinement, minimum aberration (Fries and Hunter (1980)), are commonly used criteria for selecting regular fractional factorial designs.  Both of these criteria are based on word length patterns of the designs.  In this talk, a concept of estimation index is proposed to help assess a fractional factorial design's capability to estimate factorial effects.  Furthermore, relationships among estimation index, resolution, aberration and estimation capacity are discussed.  The estimation index provides some insight into when a design is capable of entertaining the largest number of lower-order effects.  Resolution and estimation index together reveal the basic estimation capability of a design.  In addition to deriving some general results, I will also discuss the estimation capability of 8-, 16- and 32-run two-level designs by combining information about their word length patterns and estimation indices.
 

COFFEE: 3:45 p.m., 104 Snedecor Hall