A survey is a method of gauging student opinion on different topics from the class subject to how the class is run. Functionally, a survey is like a test in Blackboard with the same interface and question type.
Unlike tests, a survey is not automatically graded but Blackboard does allow the option of marking a survey completed in the gradebook.
To create a survey, go to a content page and hover over the Create Assessment and select Survey from the drop down menu.

The method for creating survey questions and assigning it to the class is identical to creating test questions.