Flipping the Classroom

Chris recently wrote an article on 'Flipping the Classroom', that was published in The Analytical Scientist. You can download it here as a pdf.

Here's the link to the article in The Analytical Scientist.

"My early teachings followed the traditional lecture format. I would spend most of the class time explaining the concepts, theories, or equations pertinent to that section of the class, including some sample problems that I would solve for the students by walking through each step.

With so many modern teaching tools at our fingertips, shouldn’t we be making more of the time we spend with our students? I decided to “flip” my classroom in an attempt to answer that question. Here is how it went:"

How it started

For the spring semester of my analytical chemistry class this year, I chose to implement the “flipped classroom”. In it, the conventional approach to teaching is turned on its head: instead of using class time to learn material in a lecture format, students use it exclusively to answer questions and work on problems. The time that the students would normally spend doing problems or homework for a traditional lecture is instead used to watch pre-recorded lectures in preparation for the work to be done in the class time. Simple!
The flipped classroom is in no way my creation – I learned of it from a seminar on teaching held at SDSU. To me, it’s the latest installment of my quest to find the best way to engage a large group of students in the beauty of analytical chemistry.

The Back Story

I have been teaching analytical chemistry at San Diego State
University since the fall semester of 2007. The course is the
traditional introductory analytical chemistry course, often
called quantitative analysis or just “quant” for short. Its focus
is to get students to think analytically about chemistry:
to begin to consider the complexities of equilibria, to
understand the statistical significance of the numbers
that they see and report, and to gain a foundation in how
accurate measurements can be made in chemistry, both in
the classroom and in the laboratory. To a large extent, it
requires the application of a lot of math to chemical systems
to understand what is happening within them. As with any
university level course, some students love it, most work
their way through it, and a few dislike it.

My early teachings followed the traditional lecture
format. I would spend most of the class time explaining
the concepts, theories, or equations pertinent to that
section of the class, including some sample problems that I
would solve for the students by walking through each step.
The problem with this approach is that it doesn’t provide
a significant amount of experience to the students. Sure,
they get to listen to me – and hopefully learn something
from that. And they get to see me solve a few problems
along the way. But it does seem like a very odd way to learn
how to do something. Would the traditional method work
if you were teaching someone to do something complex,
such as fly an airplane or perform surgery? Absolutely not!
Practical experience is crucial, which is why we have practice
problems and homework. (Does this course not have a
practical laboratory component?) But when do students
do this work? At home in the evenings? The night before
a deadline? Ever? From my experience, I would say one or
two days before the deadline is when most students try to
complete the problems. I can quite accurately gauge this by
counting the number of students that drop by my office with
questions. In a week without any homework deadlines, I had
nobody coming by. But on the week of a deadline, my office
was packed, and I was usually answering the same questions
over and over…

It is likely that many of you with lecturing experience will
have had a similar experience. I would even go so far as to
venture that, much like myself, you have probably come to
feel that you are better able to teach your students during
your office hours than you can during your lectures. After
all, it is in these office hours where you can determine what
their individual difficulties are and how to best aid. If only
all interactions could be like that. Instead, most contact
hours with your students are spent presenting a repackaged
version of the textbook or other written course material.
Given your level of education and expertise in the subject,
your time could inevitably be better spent doing something
other than what amounts to reading. Right?

Student Engagement

It was during Pittcon 2011, in the middle of our spring
semester, that I was inspired to make some serious changes
to how I would teach the analytical chemistry course. The
inspiration came from a talk by Steven Weber from the
University of Pittsburgh, who described how he got his
students to calculate the pH values for the titration curves
of various amino acids; each student was assigned an amino
acid. Steven would introduce the material and then have the
students dive into the work during class, so that he could
supervise and answer questions. The approach struck a
chord with me and I realized it could be nicely adapted for
use with my material.

With 40 students in the class there aren’t enough amino
acids for everyone, so I asked the students to work in groups.
Each group were given one of five amino acids whose pH
they needed to calculate at various points along a titration
curve, which allowed me to have numerical answers that I
could share and compare with the students. I used the first
half of the class to cover some basics related to polyprotic
titrations and then commenced the group work.
The hard part was just sitting back and letting them do
the work. Until you have actually tried to leave a lecture to
it’s own devices, it is hard to describe how uncomfortable
it feels. That doesn’t mean that it didn’t work out – but not
everything went perfectly. A couple of students adamantly
refused to work in groups and elected to leave the class.
Most students did get into groups and, after some chatting,
began the work. As I circulated around the classroom, I
answered questions that arose in each group. I also noticed
that groups were benefitting from peer mentoring, with
students helping each other.

The experiment offered two positive insights into how
effective active learning can be. The first was that many of
the students wanted to know the correct answers to the
calculations at the end of the lecture. It was great to realize
how engaged the students were with the problem. The
second sign was actually quite unexpected. Every instructor
can easily tell when there are less than five minutes left in
any class; students start to pack up their books and stop
listening entirely. But in my experimental class, this didn’t
happen. In fact, students were still working on the problems
at the end of the class when the next lecture started to enter
the room.

Given my success, I continued with the approach for the
next few years. Though it was somewhat effective in getting
a large number of students to do problems during class,
the amount of time for doing problems was rather limited.
After introducing the materials and possibly solving a
sample problem, there was little time left for group work.
Additionally, some lecture topics were not as conducive to
such an approach or simply needed more explaining. And
there was the inevitable decrease in attendance for the class,
with only a third to a half of the class attending any given
lecture, which pretty much reflected declines I’d seen when
using traditional lectures. Yes, the approach was working
pretty well, but it could certainly be improved; I was still
spending at least half of my class time lecturing, rather than
letting students work on problems or ask me questions. At
this point, the concept of the flipped classroom began to
make much more sense to me.

Learning to Flip

I should note that the implementation or rigidity of a
flipped classroom is entirely up to the instructor. I opted
for a more open structure, without any imposed deadlines
on the watching of lecture videos or the submission of
questions. Rather I had prepared problem sets (those used in
the previous years of the course) that I wanted the students
to work on in groups. For the first couple of lectures, I had
created video reviews of the labs that they would be doing
during the course of the semester. In keeping with that
theme, I provided the students with a summary of a lab, along
with the “data” collected from the analysis – a silver chloride
precipitation titration experiment. The objective was to get
the students to do the calculations for the standardization
of the titrant, during which they would need to deal with
statistical issues, such as the exclusion of outlier data points.
It was a glorious teaching plan in my mind – the students
would complete so much in just 50 minutes. It was an utter

In reality, after introducing the class and answering a
few questions, there was little more than 30 minutes left,
which was nowhere near enough for the students to grasp
the complexities of the problem. Instead of students asking
questions about the validity of data and how to interpret
results, questions revolved around how to get started.
Unfortunately, this scenario repeated itself in the next
period, as there had been no time to alter the plan. Once
again, my students were confused with material presented
to them. Clearly, I was not preparing them well enough and
had overestimated their capabilities. Fortunately, I was able
to adapt my plans for subsequent classes; I resorted to using
the problem from the more traditional format of the course,
which made classes much smoother.

I have to say that I really did not account for how much
time the lecture recordings would take out of my schedule. I
had been toying with the idea of doing a flipped classroom for some time, but never found the time to record the
lectures prior to the semester when I decided to implement
the process. As such, I found myself scrambling to prepare
videos each week for the topics to be covered. Though I had
lecture materials from my previous iterations of the course,
significant modification of those materials were necessary
to make them amenable to a lecture video. Add to that the
time to record the lecture, edit the final product, and upload
it, and the workload starts getting heavy. Sometimes I was
only able to get the lectures uploaded the day before the
class period – clearly not ideal; however, it did not prove to
be such a big problem as most students were a few lectures
behind after the first few weeks of the course.

Another surprising lesson that I learned during the
semester (which probably shouldn’t have been surprising
at all) is that, if classes are unstructured and optional,
many students will not attend. I realize this response is not
unprecedented. Certainly, in the past when I had taught
this course as a traditional lecture, I would consistently
see below 50 percent attendance in the latter third of the
semester. Some students had just given up on the course,
others made use of the course materials that I provided
(audio recordings, sample problems, lecture slides) rather
than coming to lectures directly. However, using the flipped
classroom, the decline in attendance started sooner and
went to a much lower level, with as few as a quarter of my 80
students attending lectures regularly.

Assessing the Flipped Classroom

I would be lying if I said that I didn’t want all my students to
come to every class, but the reality is that, though working
on problems in groups is a great way for most students to
learn, it does not mean it holds true in every case. Moreover,
because of the lack of strict deadlines, the course effectively
became a self-paced program; students were less likely to be
at the same point and thus less likely to be able to work in
groups. The big question is whether or not low attendance is
a problem.

In a traditional course it would clearly be problematic –
students would be missing out on the basic instruction for
the course. However, with a flipped classroom, that’s not
necessarily the case. The lecture materials (including videos,
problem sets, solutions, and online homework) are fully
available, so presence in the class is not a direct indication of
their efforts to learn the material. In fact, if the dropout rate
for the class (meaning those who did not withdraw from the
course but elected not to write the final exam), is compared
to the historical average, the change is stunning. Under the
flipped classroom approach, the only student who did not
complete the class withdrew in the first few weeks of the
course. Historically, about 10 percent will not write the final
exam, having given up before the course finishes.
I have to say, it is not fully clear whether or not the flipped
classroom approach was the principle factor in the improved
retention of the students. Other changes, including a
revision to the structure and style of exam questions may
have also played a role. However, comments from some of
the students, including one who had failed to complete the
course in the more traditional lecture format, shed some
light. In the traditional lecture format, if a student does not
grasp the material being taught, it’s rarely possible to get a
second chance. Of course, with lecture videos, the student
can replay sections over an over, so if motivated, has no
reason to fall behind in their understanding.

An inability to ask questions of the lecturer while
watching videos was inconvenient for some. But there are
two solutions to this problem: (i) email the instructor the
question or (ii), as I suggested to my students, they could
5 Featur actually opt to watch the lectures during class, where I would
be available to answer questions on the spot. Admittedly,
this takes us almost full circle, but because the recorded
lectures are much shorter than the class time allocated, it
still presented a better alternative, since I was available to
answer as many questions as required.
Over the course of the semester I elicited feedback from
my students about their feelings on the flipped classroom.
The responses varied widely – some loved the new approach
and others hated it. Complaints fell into two main
categories, students either preferred the live lectures over
the videos or wanted to see sample problems solved rather
than stepwise calculated solutions.

The craving for traditional lectures may stem from comfort
and familiarity – at least one student admitted as much in
the feedback. And yet, given the rate at which I normally
see students stop attending classes – and their total lack of
participation – I am struggling to share what benefit they
derive from a formal lecture period. The inclusion of videos
illustrating solutions to sample problems was something
that I did change. It was easy enough to accomplish with a
whiteboard, iPhone, and a camera tripod, and added a more
dynamic feel to the narration of slides.

Am I a flipping convert? Absolutely! Overall, I feel that
the flipped classroom was very successful. The students
completed the course, and did so with far better grades than
my previous traditionally taught classes. Despite the success,
I do know that I can make the flipped classroom an even
better experience for my students. Many students lamented
the low numbers attending the class times, echoing my
feelings. And while I recognize that students can be (and
often are) successful without coming to class, I would like to
be able to push the students further.
I will be redoing my videos before the start of the semester
to better integrate examples of problem solving. I will also
significantly shorten the videos, making more in the process.
After all, the traditional lecture habit of repetition is not one
that is needed when the students have access to a rewind

I see the flipped classroom as the inevitable evolution of
much of our teaching, if only for the reason that as educators
we can be far more effective when we directly engage our
students and help them solve their specific problems. Given
the success that I saw with my first – and admittedly clumsy
– attempt at flipping the classroom I see no reason to go
back to the traditional lecture format.
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