betaij
Betaij is a term that lacks a canonical definition in published literature. In practice, it has appeared in a small number of niche discussions as a label for a parameter, a variable interaction, or a hypothetical cross-term, without being standardized across disciplines.
Possible interpretations include: in statistical modeling, betaij is sometimes used informally to denote a cross-term coefficient
Origin and history of betaij are not established in a universally accepted way. The appearance of the
See also: beta coefficient, interaction term, cross-term. Given its lack of standardization, readers are advised to