Kabera, Gaëtan M.Haines, Linda M.Ndlovu, Principal2016-01-282016-01-282015-09-03The analytic construction of D-optimal designs for the two-variable binary logistic regression model without interaction 2014, 49 (5):1169 Statistics0233-18881029-491010.1080/02331888.2014.937342http://hdl.handle.net/11288/595089Candidate locally D-optimal designs for the binary two-variable logistic model with no interaction, which comprise 3 and 4 support points lying in the first quadrant of the two-dimensional Euclidean space, were introduced by Haines et al. (D-optimal designs for logistic regression in two variables. In: Lopez-Fidalgo J, Rodrigez-Diaz JM, Torsney B, editors. MODA8 – advances in model-oriented designs and analysis. Heidelberg: Physica-Verlag; 2007. p. 91–98). The authors proved algebraically the global D-optimality of the 3-point design for the special case in which the intercept parameter is equal to−1.5434. However for other selected values of the intercept parameter, the global D-optimality of the proposed 3- and 4-point designs was only demonstrated numerically. In this paper, we provide analytical proofs of the D-optimality of these 3- and 4-point designs for all negative and zero intercept parameters of the binary two-variable logistic model with no interaction. The results are extended to the construction of D-optimal designs on a rectangular design space and illustrated by means of two examples of which one is a real example taken from the literature.enArchived with thanks to Statisticstrapezium designD-optimalitybinary two-variable logistic modelno interactionstand-ardized variance functionArticleStatistics