Quality test using structured scaling
Two samples (A and B) of cooked fish were evaluated by 10 assessors using the scheme fig. 8.3. The following overall quality score was obtained.
Treatments |
Difference |
||
Assessor |
A |
B |
A - B |
1 |
7 |
7 |
0 |
2 |
8 |
7 |
1 |
3 |
6 |
5 |
1 |
4 |
7 |
5 |
2 |
5 |
7 |
5 |
2 |
6 |
8 |
6 |
2 |
7 |
8 |
6 |
2 |
8 |
8 |
6 |
2 |
9 |
7 |
5 |
2 |
10 |
8 |
7 |
1 |
Total |
74 |
59 |
15 |
Mean |
7.4 |
15.9 |
1.5 |
Standard deviation
n is number of assessor
t = 1.5/(1.643/3.165) = 2.889
From Table with n - 1 degree of freedom (probability 0.05%) t is 2.622.
Sample A is significantly different as t(2.889)> t table(2.622)
