1. Accuracy & Precision in Measurement
WATCH—Look at your watch, what time is it?
What if it were 1 hour ahead?—inaccurate, but still precise because it is moving at a CONSISTENT Rate around the dial.

2. Accuracy & Precision Accuracy: Precision:
How close you are to the actual value
Depends on the person measuring
Precision:
How finely tuned your measurements are or how close they can be to each other
Depends on the measuring tool
Determined by the number of significant digits

3. Accuracy & Precision may be demonstrated by shooting at a target.
Accuracy is represented by hitting the bulls eye (the accepted value)
Precision is represented by a tight grouping of shots (they are finely tuned)

5. Accuracy without Precision Accuracy & Precision
Begin Activity
No Precision & No Accuracy
Precision without Accuracy

6. HITTING THE MARK Make 5 balls of equal size
Drop the clay balls as close to the center of the target as possible from 1 meter height
Try different methods to maximize precision and accuracy
Write a detailed procedure
Switch your procedure and conduct 3 trials of dropping the 5 balls
Mark each spot with a colored marker.

7. Representativeness
Degree to which the samples taken from the water body represent the environmental conditions of that water

8. Completeness
Comparison of the minimum number of samples necessary tor meaningful data VS. Number of samples originally intended to be collected.

9. Comparability
How well data can be compared with other data from the same project or data from another project
PROTOCOLS / Standard Operating Procedures (SOP’s)
a collection of detailed, written instructions designed to achieve uniformity of the performance of a specific task.
A step by step instruction of how to complete the task

10. Reliability Combines: Accuracy Precision Representativeness
Completeness
Comparability

11. Ways to Increase Accruacy and Precision
Technology:
Simple Visual Observation
Calibration
Testing Kits- Company, Expiration Date

12. Data Quality Objectives
Established by EPA
Water Managers Rely on:
Physical
Chemical
Biological Assessments

13. Accuracy Precision Representatvieness Comparability Reliablilty
Procedures and protocols ensure:
Accuracy
Precision
Representatvieness
Comparability
Reliablilty
Give an accurate picture of the quality of water we are consuming and any remediation efforts that may be needed

14. Define Questions
Collect Data
Manage Data
Interpret Data
Present Data
TAKE ACTION!!!