BRAINCAKERandom and Systematic Errors
No measurement is perfect. The difference between a measured value and the true value is caused by errors, which come in two kinds.
Random errors make repeated readings scatter unpredictably above and below the mean. Causes include small changes in the surroundings, judging a reading by eye, or reaction time that varies from one go to the next. Random errors affect precision. Their effect can be reduced by taking repeat readings and calculating a mean, or by using an instrument with a finer scale or data logging, but they can never be removed completely.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
Key terms in this lesson
- precision
- How close repeated measurements of the same quantity are to one another, shown by a small spread about the mean.
- accuracy
- How close a measured value is to the true or accepted value of the quantity being measured.
More in Measurements and Errors
- SI Base Units
- Derived Units
- Prefixes
- Converting Units
- Precision, Repeatability and Reproducibility
- Resolution and Accuracy
- Absolute, Fractional and Percentage Uncertainty
- Combining Uncertainties
All 12 lessons in Measurements and Errors · All AQA AS-level Physics topics