Table 3.

Design matrix.

Sample	Coded Factor		Uncoded Factor
	V 1	V 2	V 1	V 2
S1	0	0	0.55	60
S2	2	0	0.85	60
S3	0	0	0.55	60
S4	0	0	0.55	60
S5	−1	1	0.40	70
S6	−1	−1	0.40	50
S7	0	2	0.55	80
S8	1	−1	0.70	50
S9	−2	0	0.25	60
S10	1	1	0.70	70
S11	0	0	0.55	60
S12	0	0	0.55	60
S13	0	−2	0.55	40
S14	0	−2	0.55	40
S15	−1	−1	0.40	50
S16	1	1	0.70	70
S17	−1	1	0.40	70
S18	0	2	0.55	80
S19	0	0	0.55	60
S20	0	0	0.55	60
S21	0	0	0.55	60
S22	2	0	0.85	60
S23	0	0	0.55	60
S24	−2	0	0.25	60
S25	1	−1	0.70	50
S26	0	0	0.55	60