Calculate the percentage error between observed and true values
Percentage error is a measurement of the discrepancy between an observed (measured) and a true (expected, accepted, known etc.) value. It is typically used to compare measured vs. known values as well as to assess whether the measurements taken are valid.
The computation of percentage error involves the following steps:
If the observed value is 56.891 and the true value is 62.327:
Absolute error = |56.891 - 62.327| = 5.436
Relative error = 5.436 / 62.327 ≈ 0.08722
Percentage error = 0.08722 × 100% ≈ 8.722%
When not using absolute values, a negative percentage error indicates that the observed value is smaller than the true value. A positive percentage error means the observed value is larger than the true value.