Table 2. Univariate comparison of surface roughness (Ra) using three-way ANOVA .

Tests for inter-subject effects
Surface roughness (Ra)	Type III Sum of Squares	df	Mean Square	F	Sig.
Intercept	44.230	1	44.230	196.449	0.043
Material	0.223	1	0.223	39.771	0.339
Sintering temperature	0.033	3	0.011	2.409	0.613
Holding Time	0.023	3	0.008	0.891	0.635
Material * Sintering Temperature	0.022	3	0.007	0.553	0.659
Material * Holding Time	0.035	3	0.012	0.860	0.496
Sintering Temperature * Holding Time	0.096	9	0.011	0.785	0.638
Material * Sintering Temperature * Holding Time	0.122	9	0.014	1.851	0.059