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10
Statistical Considerations in
Developing a Sampling Plan
•
Importance of a threshold for
acceptance
•
Statistical confidence based on
sample numbers
•
Role and validity of assumptions
Four quantities are needed for
the calculation of sample size:
1.
The contamination rate (P) that is
considered acceptable, or acceptable
within the practical and reasonable
confidence limits. The level at which one
would not want to take action. This is
called the Acceptable Quality Level (AQL).
2
Th
t f ti h th l t i t
.
e error ra e or ac ng w en e o s a
the AQL. This is the Type 1 error or
Producer’s risk. A typical Type 1 error is
5%.