maybe its a very stupid question but I am very desperate in the moment because nothing works… but maybe you can help me
i developed a questionnaire and now I want to prove the convergent validity. Therefore, I used an other questionaire. The people had to fill out my questionnaire and the other questionnaire. Now I want to check the convergent validity - does my questionnaire measures the same like the other one. For my understanding I need to get the correlation of both? Both questionnaire were rated on a 7 scale answer format.
Can you help me, which function do I need?