偏差

• Reading: へんさ
• Romaji: hensa
• Kanji breakdown: 偏 (hen) — partial, lean to one side; 差 (sa) — difference, gap
• Pronunciation: /hen.sa/

Meaning

Deviation; the amount by which a value differs from a standard or average. Used in statistics, meteorology, and quality control.

In statistics, 偏差 quantifies the distance between an observed value and a reference point, most commonly the mean. It forms the basis of standard deviation (標準偏差) and variance (分散). In Japanese education, 偏差値 (deviation score) is a standardised score used widely to rank students relative to the population. Also used in meteorology for temperature anomalies.

Examples

1. 標準偏差は各データ点と平均値との偏差を基に計算される統計量だ。 Standard deviation is a statistical measure calculated based on the deviation of each data point from the mean.
2. 今月の平均気温は平年値からの偏差がプラス三度と記録された。 This month's average temperature was recorded as a deviation of plus three degrees from the normal value.
3. 工場では製品の寸法偏差を一ミリ以内に抑えることが品質管理の基準となっている。 In the factory, keeping the dimensional deviation of products within one millimetre is the standard for quality control.

Usage Guide

Context: statistics, meteorology, quality control, education

Tone: analytical

Origin & History

Compound of 偏 (lean, partial, deviate) + 差 (difference, gap). The combination precisely captures the mathematical concept of a value leaning away from a central reference point.

Cultural Context

Era: Modern

Generation: Adults (academic/professional)

Social background: Academic/Professional