Affiliations: Indian Agricultural Statistics Research Institute, New Delhi, India
Corresponding author: Krishan Lal, Indian Agricultural Statistics Research Institute (IASRI), Library Avenue, Pusa, New Delhi 110 012, India. Tel.: +91 11 2584 7121 Ext. 4133; Fax: +91 11 2584 1564; E-mail: [email protected].
Abstract: Irregular two-level fractional factorial designs are the plans that can not be specified in terms of defining contrasts. The aliasing properties of irregular fractional factorial plans can be explained by using minimum moment aberration and moment aberration projection criterion. In this paper a method of construction for irregular minimum aberration fractional factorial designs of the type r2p(2k), where r is a prime number has been given. Also minimum aberration designs have been constructed for r=3, p=2 and k=4,5,6,7; for r=3, p=3 and k=5,6,7,8; for r=5, p=3 and k=5,6,7,8 and r=7, p=3 and k=5,6,7,8 by using the two criteria, viz. minimum moment aberration and moment aberration projection.
Keywords: Defining relations, irregular fractional factorials, minimum moment aberration, moment aberration projection, resolution plans