Hi I have two important questions to ask. (1) My research is a psychological research that focuses on variable A predicting variables B and C. I aim to do two separate linear regression analyses to see if variable A can predict variable B and C. In addition, I also want to see in a separate analysis if variable B which is predicted by A can be also be a moderator between the relationship of A and C. So my first question is, B was an outcome variable in regression analyses, can it also be a moderator variable?
(2) If i have not administered research instrument to measure a particular variable, but have only measured it by asking a descriptive question in demographic sheet, can it still be considered an important variable and can i use in my regression or moderation analysis?