1. First step would be creating the actual survey - just go to Administration and there choose "Surveys" tab. A survey has to have at least one page and one question, but the number is up to you.
2. Now you can choose which types of questions you need. "Scale" is a great one - just define the grades and make them understandable for users. Don't forget to make the answer mandatory!
3. The most important thing is assigning the survey to specific users. To do that, you need to create an action. All you have to do is name such action and define "Users" as its object. The system will allow you to choose users you want to complete the survey,
4. You can also define the dates of availability. It will allow you to control the stream of answers. Just set the start and end date while creating the action.