Definitions

1. Accuracy

• Definition: The degree to which a measurement is close to the true or accepted value.
• Explanation: Accuracy reflects how well a measured value matches the standard or known value. It considers systematic errors in measurements.

2. Precision

• Definition: How close repeated measurements are to each other, regardless of how close they are to the true value.
• Explanation: Precision indicates consistency among measurements and is mainly affected by random errors. High precision means the measurements are clustered closely together.

3. Random Errors

• Definition: Unpredictable variations that cause measurements to scatter around the true value.
• Explanation: These errors arise from unpredictable factors, like changes in temperature or electronic noise. They affect precision, but repeated measurements help reduce their impact.
• How to minimise:
  • Repeat measurements and calculate the average.
  • Use electronic data loggers to reduce human errors.

4. Systematic Errors

• Definition: Errors that cause measurements to consistently deviate from the true value by the same amount.
• Explanation: These errors affect accuracy and are often due to faulty equipment or flawed experimental techniques.
• How to minimise:
  • Calibrate equipment with a known standard before use.
  • Use different methods or equipment to cross-check results.

5. Repeatability

• Definition: The ability of the same experimenter to obtain the same result using the same method and equipment.
• Explanation: If a measurement can be repeated under the same conditions with consistent results, it is considered repeatable.

6. Reproducibility

• Definition: The ability of different experimenters, using different methods or equipment, to obtain the same result.
• Explanation: Reproducibility indicates that results are consistent across different conditions, which is critical for verifying experimental findings.

7. Resolution

• Definition: The smallest detectable change in a quantity that an instrument can measure.
• Explanation: Resolution refers to the instrument's sensitivity to small changes in measurement.

8. Uncertainty

• Definition: The range within which the true value is expected to lie, given a certain level of confidence.
• Explanation: All measurements have some degree of uncertainty due to limitations in equipment or measuring techniques.