偏差

1. Origins, structure, and basic meaning

• Structure: 偏差（へんさ） means the difference between a value and a mean or other reference value.
• Basic usage: Use it to compare measurements with the mean or examine items that depart from a standard.

2. Common pitfalls and similar expressions

• Specifying the reference point
  • 平均値との偏差 describes a difference from the mean.
  • 基準からの偏差 describes the degree of departure from a standard.