Changing the Source Type options for Candidates?

Summary:

Is it possible to change the way candidates fill out their source type in Taleo?

We need to be able to see what employees are referring candidates. As you can see in the report a candidate can choose “Referral” under Submission Source Type and then have the option to choose either “I am a Rockland Trust Customer”, “Rockland Trust Employee” or “Give Referral Explanation” under Submission Source (BL). When they choose “Give Referral Explanation” there is an open field for them to enter the employee’s name; however as you can see in this report very few people are entering because they aren’t choosing that option. Is there a way this can be fixed so they