I often encountered a common issue where some of the data appeared to be from participants who were not performing the tasks diligently.
With this paper I agree with the examination of user classification this is very important because the data shows that participants who don't perform the task the right away don't know what they are doing and are not understanding the topic well. I can relate that when I do the task the right and correct way first it all makes sense and second you are doing it the correct way and it states in the second paragraph to the paper that what the key findings was and all of the data to it.