Runs Combination The mechanism interactions effects ${X}_{1}$ ${X}_{2}$ ${X}_{3}$ ${X}_{4}$ ${X}_{1}{X}_{2}$ ${X}_{1}{X}_{3}$ ${X}_{1}{X}_{4}$ ${X}_{2}{X}_{3}$ ${X}_{2}{X}_{4}$ ${X}_{3}{X}_{4}$ ${X}_{3}{X}_{4}$ ${X}_{1}{X}_{2}{X}_{4}$ ${X}_{1}{X}_{3}{X}_{4}$ ${X}_{2}{X}_{3}{X}_{4}$ ${X}_{1}{X}_{2}{X}_{3}{X}_{4}$ 1 (1) −1 −1 −1 −1 1 1 1 1 1 1 −1 −1 −1 −1 1 2 ${x}_{2}{x}_{4}$ −1 1 −1 1 −1 1 −1 −1 1 −1 1 −1 1 −1 1 3 ${x}_{1}{x}_{3}$ 1 −1 1 −1 −1 1 −1 −1 1 −1 −1 1 −1 1 1 4 ${x}_{1}{x}_{2}$ 1 1 −1 −1 1 −1 −1 −1 −1 1 −1 −1 1 1 1 5 ${x}_{2}{x}_{3}$ −1 1 1 −1 −1 −1 1 1 −1 −1 −1 1 1 −1 1 6 ${x}_{1}{x}_{2}{x}_{3}{x}_{4}$ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 7 ${x}_{3}{x}_{4}$ −1 −1 1 1 1 −1 −1 −1 −1 1 1 1 −1 −1 1 8 ${x}_{2}{x}_{4}$ −1 1 −1 1 −1 1 −1 −1 1 −1 1 −1 1 −1 1 9 ${x}_{2}{x}_{4}$ −1 1 −1 1 −1 1 −1 −1 1 −1 1 −1 1 −1 1 10 ${x}_{1}{x}_{2}{x}_{3}{x}_{4}$ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 ${x}_{3}{x}_{4}$ −1 −1 1 1 1 −1 −1 −1 −1 1 1 1 −1 −1 1 12 ${x}_{1}{x}_{4}$ 1 −1 −1 1 −1 −1 1 1 −1 −1 1 −1 −1 1 1 13 (1) −1 −1 −1 −1 1 1 1 1 1 1 −1 −1 −1 −1 1 14 ${x}_{2}{x}_{3}$ −1 1 1 −1 −1 −1 1 1 −1 −1 −1 1 1 −1 1 15 ${x}_{1}{x}_{3}$ 1 −1 1 −1 −1 1 −1 −1 1 −1 −1 1 −1 1 1 16 ${x}_{2}{x}_{3}$ −1 1 1 −1 −1 −1 1 1 −1 −1 −1 1 1 −1 1 17 (1) −1 −1 −1 −1 1 1 1 1 1 1 −1 −1 −1 −1 1 18 ${x}_{1}{x}_{4}$ 1 −1 −1 1 −1 −1 1 1 −1 −1 1 −1 −1 1 1 19 ${x}_{1}{x}_{3}$ 1 −1 1 −1 −1 1 −1 −1 1 −1 −1 1 −1 1 1 20 ${x}_{1}{x}_{2}$ 1 1 −1 −1 1 −1 −1 −1 −1 1 −1 −1 1 1 1 21 ${x}_{1}{x}_{2}{x}_{3}{x}_{4}$ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 22 ${x}_{3}{x}_{4}$ −1 −1 1 1 1 −1 −1 −1 −1 1 1 1 −1 −1 1 23 ${x}_{1}{x}_{4}$ 1 −1 −1 1 −1 −1 1 1 −1 −1 1 −1 −1 1 1 24 ${x}_{1}{x}_{2}$ 1 1 −1 −1 1 −1 −1 −1 −1 1 −1 −1 1 1 1