Table 7 Factorial design of two levels and four factorsa.
Treatment | Factors | |||
|---|---|---|---|---|
A | B | C | D | |
1 | − | − | − | − |
2 | + | − | − | − |
3 | − | + | − | − |
4 | + | + | − | − |
5 | − | − | + | − |
6 | + | − | + | − |
7 | − | + | + | − |
8 | + | + | + | − |
9 | − | − | − | + |
10 | + | − | − | + |
11 | − | + | − | + |
12 | + | + | − | + |
13 | − | − | + | + |
14 | + | − | + | + |
15 | − | + | + | + |
16 | + | + | + | + |