Table 2. Experimental trials of the Plackett-Burman factorial design (PBD).
| Essay | Plackett-Burman design variables | |||||||
|---|---|---|---|---|---|---|---|---|
| N° | X 0 | X 1 | X 2 | X 3 | X 4 | X 5 | X 6 | Y (Abs 411 nm) |
| 1 | 1 | +1 | -1 | +1 | -1 | -1 | -1 | 0.0604 |
| 2 | 1 | +1 | +1 | -1 | +1 | -1 | -1 | 0.1547 |
| 3 | 1 | -1 | +1 | +1 | -1 | +1 | -1 | 0.9964 |
| 4 | 1 | +1 | -1 | +1 | +1 | -1 | +1 | 0.1881 |
| 5 | 1 | +1 | +1 | -1 | +1 | +1 | -1 | 0.8948 |
| 6 | 1 | +1 | +1 | +1 | -1 | +1 | +1 | 1.2908 |
| 7 | 1 | -1 | +1 | +1 | +1 | -1 | +1 | 1.5373 |
| 8 | 1 | -1 | -1 | +1 | +1 | +1 | -1 | 0.1829 |
| 9 | 1 | -1 | -1 | -1 | +1 | +1 | +1 | 0.3085 |
| 10 | 1 | +1 | -1 | -1 | -1 | +1 | +1 | 0.6576 |
| 11 | 1 | -1 | +1 | -1 | -1 | -1 | +1 | 0.8053 |
| 12 | 1 | -1 | -1 | -1 | -1 | -1 | -1 | 0.0235 |
| 13 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.5341 |
| 14 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.4032 |
| 15 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.5375 |
| Σ (Sum) | 8 | 0 | 0 | 0 | 0 | 0 | 0 | |