Table 2 Identification rules used in the refined H–O specification.
From: A flexible way to study composites in ecology using structural equation modeling
Free weights (Unknown weights composite) | Unit weights (Fixed weights composite) | |
|---|---|---|
(1) Rule | Fix the sum of the loadings of the composite of interest to 1 (effects coding method), fix one of the loadings of the composite of interest to 1 (reference variable method) or fix the variance of the composite of interest to 1 (variance standardization method). | Fix the sum of the loadings of the composite of interest to 1 (effects coding method). |
(2) Rule | Fix all loadings per excrescent variable to 0 except two of them. No excrescent variable is allowed to be connected to the exact same two components and no component is allowed to load on more than two excrescent variable. | |
(3) Rule | Fix one of the two remaining loadings per excrescent variable to 1 (reference variable method). No component is allowed to serve several times as reference variable. | Fix the remaining loadings per excrescent variable in such a way that their sum equals 0, e.g., to -1 and 1. |
(4) Rule | Fix the covariances between the excrescent variables and the composite of interest to 0. | |
(5) Rule | Connect the composite of interest with at least one other variable of the model besides its components. | |
