Module 1: Experimental Design for Monitoring

Introduction ...................................................................................................................................................1 Experimental Design: Sampling Number and Frequency.............................................................................2 Sampling Plans ..........................................................................................................................................................2 Example Use of Stratified Random Sampling Plan ...............................................................................................3 Factorial Experimental Designs.................................................................................................................................4 Number of Samples Needed to Characterize Conditions...........................................................................................8 Types of Errors Associated with Sampling .........................................................................................................11 Determining Sample Concentration Variations ...................................................................................................13 Example of Log10 Transformations for Experimental Design Calculations ........................................................14 Example Showing Improvement of Mean Concentrations with Increasing Sampling Effort..............................15 Determining the Number of Sampling Locations (or Land Uses) Needed to be Represented in a Monitoring Program ...............................................................................................................................................................16 Determining the Number of Samples Needed to Identify Unusual Conditions .......................................................20 Number of Samples Needed for Comparisons between Different Sites or Times...................................................21 Need for Probability Information and Confidence Intervals....................................................................................23 Summary: Experimental Design for Monitoring ..........................................................................................24 References..................................................................................................................................................25 Appendix A: Sampling Requirements for Paired Tests...............................................................................25