also: カッパー
The Greek letter Κ/κ, used in mathematics, physics, and other technical fields. The reading カッパ is standard; カッパー is a less common variant.
In statistics, the kappa coefficient is a measure of agreement.
The Κ in this formula represents a constant.
From Greek κάππα (káppa), via English or other European languages. The reading カッパ reflects the modern Greek pronunciation, while カッパー may be influenced by English.