Once the unidimensionality of the virtual empathy scale had been checked, we created a variable from the sum of all the items, with the overall variable of virtual empathy ending up on a scale of 33 to 132 points.
This error, in turn, is a function of the magnitude of the discrimination indices, that is, the strength of the association of the items with the latent variable.
The factor load showing the Pearson's correlation coefficients of all Xerostomia Inventory-Dutch version items with the latent variable 'xerostomia' is shown in Table 1.
If the Rasch model does not fit, a more general model can be used such as a two-parameter IRT model that includes a discrimination parameter for differentially weighting the association of items with the latent variable.
However, because of the strong first factor, the substantial correlation of all items with this latent variable, and the low prevalence of the items related to the second factor, we considered perceived chewing ability as a construct that could be characterized by a summary score.
In the absence of a specific reporting guideline, there are a range of items which are reported with variable frequency.
In the absence of objective criterion standards for evaluating an absolute estimate of PA, the consistency of items on IPAQ with variables known to be related to PA, such as BMI, blood pressure, heart rate, indicators of lipid and glucose metabolism, and fitness index have been used as important construct validity measures.
5 49 50 Despite these issues, the validity coefficients in our study were remarkably similar to those reported in other studies, 5 7 8 24 30 33 39 and the consistency of items on IPAQ with variables known to be related to PA, such as BMI, blood pressure, heart rate, indicators of lipid and glucose metabolism and fitness index have previously been used as important construct validity measures.
The CDPM comprises 4 blocks: antecedent variables scale with 24 items, scale of medical burnout syndrome with 12 items, consequent variables scale with 16 items, and scale of positive personal resources with 16 items.
