I am doing peer review on a paper submission for a journal, and I am somewhat out of my depth.
The authors are developing a psychometric scale. They did a pilot study with 45 items. They measured Cronbach alpha and found that it is 0.89 overall.
Then they found that six items have
Cronbach's alpha if item deleted of 0.89 or very similar (between 0.89 and 0.893). They show a table with all six. They then write
A number of modifications were made according to what Table 2 suggested
And go on to explain how the wording of each item was changed to make it clearer. Obviously, they didn't want to have items whose
Cronbach alpha if deleted is the same as the overall Cronbach alpha.
Why are they doing this? Is this a common technique in constructing psychometric scales? Are there guidelines for doing it?
They also don't cite any literature about the method they followed to develop their scale. It does look sound overall (pilot study, exploratory factor analysis, then refining the questionnaire based on the results), but I'm not sure whether the decisions they make about details (such as the above change of six items) are justified. Is the knowledge how to make a scale so common that there is no need to cite sources?