ISPAM Meeting Book

9/17/2015

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%.

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