Questionnaire on use/exclusive use of online portal?

HI..!!!
I am doing my MBA in HR and recently I have completed my summer internship and project given to me was 'Judging the efficiency of different sources of recruitment'. And I need help in making a questionnaire on online portals which they use or don't use. Like if they only use naukri.com and no other online portals so I need to make questionnaire that why don't they use other portals? why just they use naukri.com? like that..... And need only open ended questions
So need some suggestions on that..............

Dear Srishti,
The best way to go about is design a questionnaire yourself, attach it to your post and then seek help to improve upon it. Whom all will you send the questionnaire or will you be just posting it here?

Thanks for the suggestion...
I need to get it filled from my company's HR Department and attach it to my report.