1. Random Errors๏ƒ

Random errors cause unpredictable variation between measurements.

Key features

  • Results vary unpredictably around the true value

  • Precision is reduced

  • Averaging improves reliability

Common random error

Source

Error Type

Explanation

Fix / Reduce byโ€ฆ

Instrumental

Resolution limitation

Estimation between scale divisions varies.

Use a higher-resolution instrument; repeat and average.

Procedural

Minor technique variation

Small unavoidable variations between trials.

Standardise procedure; increase number of trials.

Environmental

Temperature fluctuation

Small uncontrolled changes affect readings.

Shield apparatus; complete trials in a single session.

Environmental

Vibration / interference

Readings fluctuate due to instability.

Isolate apparatus from the source of vibration.

Fill in the Gaps โ€” Random Errors

Complete the following by filling in the missing words.

Word list (A โ†’ Z): averaged โ€ข increased โ€ข isolated โ€ข repeated โ€ข standardised

  1. Measurements should be ______________ and ______________ to improve reliability.

  2. The number of trials should be ______________ to reduce the effect of random variation.

  3. Experimental procedures should be ______________ to minimise variation between trials.

  4. Apparatus should be ______________ from sources of vibration or interference.

Reveal Answer Key

  1. repeated, averaged

  2. increased

  3. standardised

  4. isolated