Measuring entrepreneurial characteristics in teenagers

Hi,
I am going to take a written test from a large number of teenagers. I am wondering if it is better to ask questions directly or give them some stories and then ask some questions based on that story.
My worry is about the context of the story and how it may not be applicable to all students. How should I deal with it?
for example, to measure need for achievement, I have written a story which is about a student who is very good and wants to be the first. Then I will ask the respondents to put themselves in her shoes and answer some questions. However, if a student is not very good in studying, this context of need for achievement may not be applicable to him/her. What should I do?
Is this a valid method for assessing characteristics of teenagers?