Key Stage 4
Meaning
Results are precise if they given to a large number of significant figures.
About Precision
- Results may be said to be precise if each repeated results is close to the same value.
- The smaller the uncertainty the greater the precision.
- Precision is achieved by:
- Using instruments with a high resolution.
- Controlling variables so that readings are stable over a long period of time. Sometimes readings fluctuate so they cannot be recorded to as many significant figures as the instrument shows.
Accuracy vs Precision
- The number pi is 3.14159265359 correct to 12 significant figures.
- 3.1 is an accurate value for pi but it is not very precise - Close to the real number, but not many significant figures.
- 3.2111 is a precise value for pi but it is inaccurate - Not close enough to the real number, but has several significant figures.