Self paced mastery learning is great and it's also a disaster

I've been using a variation of mastery learning in both my blended course and regular courses, where students don't move on from a topic until they mastered it. They would watch videos on a topic, and then progress at their own pace through lab activities, conceptual questions, and problem sets.

It was great because it allowed me the time during class to interview students during each step of their progression to identify any misconceptions. And it prevented students from moving on until they proved that they really understood.

It was a disaster because at least half of the students were unable to work at a decent pace and budget time accordingly without putting everything off until the last possible moment. Even when I gave zeros in the gradebook if they didn't complete something that day, many students still could not manage to move at a steady pace.

I really wish it would have worked. The personal interviewing component at every step was so powerful it is hard to abandon it. But people seem to need a hard deadline at a particular point in time for each assignment in order to muster the motivation to get anything done. This sounds obvious to me now. I guess I was blinded by all the potential benefits that self pacing can provide (mastery learning, more one on one time with students, etc.)

So, I am also going back to using a more traditional non-self paced, non-mastery based class with hard deadlines. We will all move together through the material at the same speed. Some students will have to move on before they are ready, but we should be able to move at a respectable pace now. Plus the students are actually welcoming the change. They know that most of them need a rigid deadline for each assignment or they won't get it done.