Rather than take midterms and a final, freshmen in 3.091 this fall will earn their grades by answering a series of around 40 online questions spread out over the semester.
For each of around 40 topics in Introduction to Solid-State Chemistry, students will have a two-week window to head to an Athena cluster to solve a uniquely generated problem within that topic. A student who gets it wrong will be able to ask a proctor for an explanation and come back the next day to try a different problem within the same subtopic.
This latest experiment in MIT’s on-campus education is Professor Michael Cima’s twist on the ‘flipped classroom,’ in which students are first exposed to topics not during lecture but on their own time.
In 3.091 this fall, students will go through sequences of video clips and simple exercises, to be largely taken from the online version of 3.091, which 40,000 students around the world signed up for in the past year on edX, the platform for massive open online courses (MOOCs) started by Harvard and MIT.
“I’m going to take advantage of the fact that we finally have a text that’s perfect for the class,” he said, referring to the edX ‘learning sequences.’
Cima hopes that these learning sequences, which break down past lectures into shorter segments, will save time for those who remember their high-school chemistry.
“Some students have a background in the Bohr atom. They don’t need to mess with that. Moles to grams? They can just skip right by that.”
Cima also hopes the learning sequences will free up time for livelier classes.
“My lectures are going to be very different. I am not going to get up to the board and go through laboriously the kind of things I was forced to before because it was not even in the text,” he said. “Now I can take more questions. I can spend more time making sure people get the big picture. I can do more demos, which I plan to do. I can spend time putting questions to people in the audience, getting a discussion going, which I personally feel I’m much better at than talking at a chalkboard.”
As for splitting up the tests into bite-sized online assessments, Cima said the switch was borne of doubts that traditional exams were working.
When grading midterms, Cima said he often came across problems left blank.
“Does that mean the student didn’t know this? Or does it mean I didn’t test this? In other words, they didn’t have time. I believe it’s that they didn’t have time.”
Students will have up to several hours to do one problem this fall — the plan is for 3.091 TAs to “take over” an Athena cluster for some fraction of each week, including from 7 to 10 p.m. each night. Students will be allowed to come in at any time within that period.
Cima said that when he looked over the final, three midterms, and 10 or 12 quizzes from semesters past, he found that there were 37 problems, corresponding to around the same number of topics.
A team has been working through the summer to create a collection of problem templates for each of these topics. Simply by randomly varying the numbers, each template can spawn any number of different problems for the student at the Athena terminal.
It’s an approach that’s been tested on the students in the edX course. The edX team wrote 15 problem templates about acids and bases, and each student was assigned a random template with random numbers within bounds. “Over the entire world, no one got the same question,” Cima said, and to his knowledge, “nobody knew this was going on.”
Cima said he enjoys interacting with students on edX’s discussion forum. “The students like it when the ‘professor’ responds to a question or cheers them on in some way.”
Still, his MIT students take priority. “The only reason I got involved in this is I want to do a better job in my residence class,” he said.
In an experiment with grading open-ended responses with artificial intelligence, Cima asked edX students to answer a question about surfactants in five sentences or fewer. 100 of the responses were graded by hand and used to train the automated grader.
Though the experiment in machine learning was unsuccessful, Cima did come out with an insight that may forever change the way he assesses students.
The tests MIT students have been handing in? “All different angles — you can’t read it.”
“What I learned about [typed] responses is that they are tremendously easier to hand-grade than a hand-written response from a student,” he said. “It took me like a fraction of the time — boom, boom, boom, boom.“