A scenario task is a set of steps that the participant needs to perform to accomplish a goal. Once you’ve figured out what tasks you want to test, you’ll need to formulate some realistic task scenarios for participants to accomplish. In short, a task scenario is the action that you ask the participant to take by providing the necessary details to accomplish that task.
A scenario task should be given to the participant during the usability test and they should represent what these people actually do with that software. Scenario tasks are the best way to bring to light usability issues since you can really see the way the participant is trying to finish the task given by you. These tasks should be created carefully because their formulation determines the reliability and the validity of the overall usability testing.
Before I applied for Outreachy internship I had to present a “first contribution”, in my case a usability test with few testers and ten scenario tasks. This test served as a glimpse on how the final usability test result would look like, and also gave me more information on what I should and should not be doing next time while creating scenario tasks and while performing those tasks. I managed to summarize three short tips on how to create better scenario tasks: