Questionnaire Validation with two different rating scales

scale-validation

#1

Hello. I want to check the validity of a questionnaire,

I want to check the validity of a questionnaire by correlating it with other questionnaires.
The problem is that the questionnaires have different response scales (1-5, 1-7, 1-6).
I don’t know how the correlation works.

I used the psych package with the function:

data(bfi)
keys.list <- list(agree=c("-A1",“A2”,“A3”,“A4”,“A5”),
conscientious=c(“C1”,“C2”,“C3”,"-C4","-C5"),extraversion=c("-E1","-E2",“E3”,“E4”,“E5”),
neuroticism=c(“N1”,“N2”,“N3”,“N4”,“N5”), openness = c(“O1”,"-O2",“O3”,“O4”,"-O5"))
keys <- make.keys(bfi,keys.list) #no longer necessary
scores <- scoreItems(keys,bfi,min=1,max=6) #using a keys matrix
scores <- scoreItems(keys.list,bfi,min=1,max=6) # or just use the keys.list
summary(scores)

Does anyone know how to handle the different rating scales?
Thx a lot !


#2

This being a general stat question may be better suited to stats.stackexchange.com