Functionality and Skill

noun

• Capable of serving a purpose well.
  • usage: "software with greater functionality"

noun

• An ability that has been acquired by training.
  • synonyms: accomplishment, acquirement, acquisition, attainment
• Ability to produce solutions in some problem domain.
  • usage: "the skill of a well-trained boxer"; "the sweet science of pugilism"
  • synonyms: science

• (n.) The familiar knowledge of any art or science, united with readiness and dexterity in execution or performance or in the application of the art or science to practical purposes; power to discern and execute; ability to perceive and perform; expertness; aptitude; as, the skill of a mathematician, physician, surgeon, mechanic, etc.
• (n.) Display of art; exercise of ability; contrivance; address.
• (n.) Knowledge; understanding.
• (v.t.) To know; to understand.
• (v.i.) To make a difference; to signify; to matter; -- used impersonally.
• (n.) Any particular art.
• (n.) Discrimination; judgment; propriety; reason; cause.
• (v.i.) To be knowing; to have understanding; to be dexterous in performance.

Skill is the ability to accurately forecast returns. We measure skill using the information coefficient.