eng Science and Education Publishing Applied Mathematics and Physics 2333-4886 2020-10-13 8 1 20 25 10.12691/amp-8-1-4 AMP2020814 article Njoroge Elizabeth Wambui 1 Koske Joseph 2 Mutiso John 2 Dpartment of Physical Sciences, Chuka University, P.O. Box 109-60400, Chuka, Kenya Department of Mathematics, Physics and Computing, Moi University, P.O. Box 3900, Eldoret, Kenya This paper aims at investigating and comparing the D- and G-optimal criteria for non-pure blends slope designs. The study used a parameter subsystem of interest based on the second-degree Kronecker model to obtain the H-invariant information matrices for both Equally Weighted Simplex Centroid Axial Design and Un-equally Weighted Simplex Centroid Axial Design. The D- and G- optimal values worked out revealed that the centroid achieved the best D- and G-optimality values and that the best D-efficient and G-efficient design points were with 105.71% and 99.76% respectively. The latter design was more D-efficient while former design was more G-efficient. http://pubs.sciepub.com/amp/8/1/4/amp-8-1-4.pdf axial design subsystem H-invariant centroid D-optimal G-optimal efficiency