In a validation study, I know that reporting internal consistence of the instrument which is validated in total and its subscales are important. But which is of priority to report in articles? Cronbach's Alpha Based on Standardized Items or cronbach alpha?
I know the difference too:
The first Cronbach's alpha employs the covariances among the items, whereas the alpha based on standardized items employs the correlations among items. The latter alpha is based on the assumption that all of the items have equal variances, which is often false in practice.
But I still dont know which one is more important in a validation study.
Cronbach's Alpha Based on Standardized Items is used when the response option of your scale change in your questionnaire. Let you have three items and one have five response option, second is four response options, third is three response options. Because your items in different metrics you have to standardize them before your reliability analysis. Thus, Cronbach's Alpha Based on Standardized Items standardize your items (mean= zero, standart deviation=1, or z score) and use these standardized items in your reliability analysis. If your items metric is the same in all items using above example, your all items have the same response options let five, you can use Cronbach's Alpha. The differance is that. however, the difference is often very small in both.
Your question answer is up to me Cronbach's Alpha ıf the response option of your scale is same.
Dont forget ıf you have subscales report reliability (item total and Cronbach alpha) based on subscales not total scale.
Best wishes.
