回帰

• Reading: かいき
• Romaji: kaiki
• Kanji breakdown: 回 (kai) — to return, to revolve; 帰 (ki) — to return home, to revert
• Pronunciation: /ka.i.ki/

Meaning

Regression; return; recurrence. In statistics, the process of finding the relationship between variables; more broadly, a return to a former state.

A multifaceted noun with both a general meaning (returning to an origin or previous state) and a specific statistical meaning (regression analysis — 回帰分析). In data science and machine learning, 回帰 specifically refers to regression models that predict continuous values, contrasted with 分類 (classification). In biology and medicine, it can refer to the recurrence of a disease. The compound appears in 線形回帰 (linear regression) and 論理回帰 (logistic regression).

Examples

1. 機械学習では、回帰モデルを使って気温や株価などの連続値を予測する。 In machine learning, regression models are used to predict continuous values such as temperature and stock prices.
2. 統計的回帰分析により、変数間の相関関係を定量的に明らかにすることができる。 Statistical regression analysis enables the quantitative clarification of correlations between variables.
3. 癌の回帰を防ぐため、患者は定期的な検診を受けることが推奨されている。 To prevent cancer recurrence, patients are advised to undergo regular medical check-ups.

Usage Guide

Context: statistics, data science, machine learning, medicine, academic writing

Tone: technical, neutral

Origin & History

Sino-Japanese compound: 回 (kai) — to return, to revolve + 帰 (ki) — to go back, to return home. Used in classical Japanese to mean 'returning' and adopted in Meiji-era scientific translation to render 'regression' in its statistical sense.

Cultural Context

Era: Meiji-Modern

Generation: Adult

Social background: Educated