In this screencast I'm going to describe some of the reasons that we've prepared screencasts
for chemical engineering courses at the University of Colorado, and made them available online.
The location of these screencasts is on learncheme.com as well as on YouTube and ITunes U and there
are various forms.
As you can see in general they are handwritten, they're short, they describe some process,
some example problem in chemical engineering.
For those of you who teach, you would like to get this type of feedback from students
where they talk about lectures, they really like the textbook.
These are the kind of comments that certainly would be appreciated if you teach, but in
general they're not the kind of comments we receive in our courses.
However, these are indeed direct quotes from anonymous student feedback at the end of the
semester in our courses where we ask them about screencasts.
The fact that in a thermodynamics course they say they love the screencasts, they think
they're incredibly useful, unbelievably effective.
This is part of our motivation for preparing these screencasts.
So what is a screencast?
It's not someone at a board lecturing for 50 minutes on a number of topics, instead
it's a short video.
It might be explaining a diagram, or explaining how to use a certain type of software, solving
an example problem, introducing a topic, and these are made on a tablet PC, using screen
capture software, Camtasia.
They're typically on the order of 3 to 10 minutes, and they cover just one topic.
That's an important distinction from the lecture.
Also they do not include a person, they strictly show the screen capture.
So why screencasts?
Well certainly some of the advantages over a textbook is that you can use color, but
you can also introduce things sequentially.
That's more difficult to do in a textbook.
For example, an equation in thermodynamics where we can indicate what this term is equal
to, and then slowly indicate the other term, and then these things that are shown here
were done sequentially so that these lines that are in the last part here are not all
introduced at once but they're introduced one at a time and explained as they're introduced.
Similarly, if we were talking about something like a triple-effect evaporator, if this was
in a textbook what we would see is a diagram, black and white, showing a triple-effect evaporator
completely, and then lower on the page, or on the next page would be a description of
that diagram.
And this can certainly create cognitive overload for someone trying to both visually look at
the figure and then read the text.
It’s much more effective if the figure is presented with an oral description in the
screencast and the text is not also written down.
So we can do things sequentially with color, and I won't show the sequential process but
you could look at a screencast to see this.
The idea is that we start with the diagram in the upper right corner here and then we
step-by-step add the various other parts.
Add the flow streams and use color to make it easier to distinguish where the flow is
going.
So why use screencasts?
Well certainly there are studies that say they improve student learning, and that's
one of the motivations.
From a student's viewpoint, the fact that they're available 24/7, that's a big difference
over the need to get to office hours at a certain time to get an explanation of a topic.
Also, unlike in class, students can control the pace.
They can start them, stop them, replay them, and, as I showed earlier, students very definitely
like them and use them without being assigned them.
They're short so they're focused on one topic.
This makes them very modular, you can pick one and then use number four and number twelve,
very flexible.
They're sustainable, once they're prepared and posted online they can be used for a long
time.
If a mistake is identified they can be corrected.
Doesn't require printing the next version of the textbook to correct the mistakes.
I'll present just a couple examples that demonstrate their value.
In this particular high school they went to a flipped classroom concept, meaning what
traditionally was done at home, homework problems for example, was done in class.
What's traditionally done in class, delivering information, is done at home via videos, screencasts,
and they saw a dramatic drop in the failure rate of their courses when they started doing
this.
A controlled study that was part of a PhD thesis that looked at one topic, chemical
equilibrium, and compared a 50 minute lecture to a 50 minute lecture plus an 11 minute screencast.
So just an additional 11 minutes but in the form of a screencast.
The pretest showed these two groups were equally good, or bad.
They answered 3.1 out of 14 questions.
The post test on the topic showed a small improvement for the 50 minute lecture.
But adding just an additional 11 minutes of a screencast caused a much larger improvement.
So that they additional number of correct more than doubled.
If you look at the difference, there's five more correct with the screencast, there’s
two more correct with the lecture.
So a really dramatic difference by using screencasts.
One of the other reasons we think they're valuable and useful is they can be easy to
prepare.
We do a single recording, in other words, we do not do multiple takes to try and make
it perfect.
This means the preparation time can be relatively short, we can certainly pause at times to
write something down.
So just like I paused I could write something on the tablet with a pen and then resume.
I can scroll back to show something previously, and then we can post process, we can remove
dead times during the recording.
If we make an error we can cut it out.
We can also add callouts and highlights or zoom in on some figure for example to make
it clearer.
We have prepared screencasts for chemical engineering courses because studies also show
they are effective for student learning.