| |
| 3 - Historic |
 |
| Scheffé's firt applications in 1960's: |
| |
chemistry, oil industry, cake formulations... |
|
| Advantages : |
| |
Low number of tests
Easy-reading representation
Best mix proportions determination
No limits in components number... |
| |
|
| 4 - Number of components studied |
|
| Is it possible to study more than 3 species interactions ? |
| In theory: no limit in component numbers...BUT the number of tests to perform increases rapidly with the number
of components ! |
| |
Interactions |
Components
number |
Linear |
Quadratic |
Cubic
simple |
Cubic
full |
| 1 |
1 |
|
|
|
| 2 |
2 |
3 |
|
|
| 3 |
3 |
6 |
7 |
10 |
| 4 |
4 |
10 |
14 |
20 |
| 5 |
5 |
15 |
25 |
35 |
| 6 |
6 |
21 |
41 |
56 |
| 7 |
7 |
28 |
63 |
84 |
| 8 |
8 |
36 |
92 |
120 |
| 9 |
9 |
45 |
129 |
165 |
| 10 |
10 |
55 |
175 |
220 |
|
| 3 to 4 species leads to double the number of components |
|
|
Scheffé’s method allow
to study a property as a function of component proportions only.
