In this paper, a comprehensive parametric study on the effects of operating parameters in wire electrical discharge turning (WEDT) process was conducted. Total of eleven operating parameters were considered against the machined surface quality. The research focuses on the micro-turning of Ti6Al4V materials using Taguchi’s L12 orthogonal array at two level experimental designs. Analysis of variance (ANOVA) and signal-to-noise (S/N) ratio were used as statistical tools to evaluate the significances of the parameters. It was found that among the eleven operating parameters, only four parameters dominated and have statistical significant effects on the surface roughness values as discovered by ANOVA. The operating parameters were the rotational spindle speed (28.34%) as the most dominating... factor, followed by intensity of pulse (24.18%), wire tension (20.57%) and stabilizer E (11.97%).notion of weight structure, and proved that the category DMgm(k) of geometrical motives over a perfect field k, as defined and studied by Voevodsky, Suslin and Friedlander [Cycles, transfers, and motivic homology theories, Annals of Mathematics Studies, vol. 143 (Princeton University Press, Princeton, NJ, 2000)], is canonically equipped with such a structure. Building on this result, and under a condition on the weights avoided by the boundary motive [J. Wildeshaus, The boundary motive: definition and basic properties, Compositio Math. 142 (2006), 631–656], we describe a method to construct intrinsically in DMgm(k) a motivic version of interior cohomology of smooth, but possibly non-projective schemes. In a sequel to this work [J. Wildeshaus, On the interior motive of certain Shimura varieties: the case of Hilbert–Blumenthal varieties, Preprint (2009), 0906.4239], this method will be applied to Shimura varieties.