Measurement & Experimental Science
Accuracy, Precision & Measurement Uncertainty
Measurements contain uncertainty. Precision describes repeatability; accuracy describes closeness to a true or accepted reference, and the two are not the same.
Key concepts
- A precise instrument can still be biased
- Resolution is not the same as accuracy
- Biological measurements add sampling variability
- Report methods and units so values can be interpreted
What to measure or observe
- Repeat measurements to estimate short-term variability
- Check instruments against standards where possible
- Use consistent units and significant digits
- Record sensor model and method for important datasets
Common mistakes
- Reporting more decimal places than the method supports
- Calling two slightly different readings biologically meaningful without context
- Ignoring calibration drift
Visuals this lesson still needs
- Accuracy-versus-precision target diagram
- Resolution-versus-accuracy example
- Uncertainty range graphic
- Calibration drift timeline