Many past investigations of family members’ perceptions of their relative influence in family decision making show a lack of convergence in multiple reports. This, in turn, represents a serious threat to validity in attempts to depict the structure of family decision influence. These studies warn against using single-item measures of family members’ influence even in cases involving multiple respondents. In this study, using multiple-respondent, multiple-item data, the authors develop triadic measures of children's influence in four categories of product purchase decisions that exhibit desirable levels of convergent and discriminant validity. The process of measure development and validation demonstrates a methodology that combines the traditional measure purification process, confirmatory factor analysis, and multiple-influence, multiple-rater data analysis procedures.
The development and validation of a novel outcome measure to quantify mobility in the dysvascular lower extremity amputee: the amputee single item mobility measure
