Screencasts have a number of advantages over other methods for delivering information and
for learning.
One of the significant advantages that we have observed is when we have diagrams that
we need to introduce and explain, and from chemical engineering examples or things like
a TX-Y diagram or explaining miller indice planes in a crystal structure.
a process flow diagram for a distillation tower or a McCabe Thiele diagram to analyze
the concentrations in the distillation tower or pressure-temperature-temperature diagram.
I could make a long list here.
The advantages are: 1.
that we can introduce the information sequentially, this is certainly one of the big advantages.
For example, in a textbook where we might be looking at a double-effect evaporator diagram,
we would see something presented in a figure that looks like this.
Although certainly drawn more neatly, and so everything is given at once, and for students
they have to understand the various processes and where the flow streams are going, and
there's some significant advantages instead to introduce things one at a time.
For example, showing just the containers.
Then we're going to sequentially introduce the flow streams.
The other advantage I'm demonstrating here is we can use color to make it clearer we're
talking about a liquid inside a container.
And then we can precede as we describe the process to say that we have coming into the
heat exchanger, steam, which condenses and then leaves as a liquid at saturation conditions.
Coming in to liquid is our feed and this has some composition.
We're going to evaporate some of the liquid to make a vapor, and then the concentrated
solution now leaves at the other end and by using color we can demonstrate the differences
in the process.
We're now going to take the vapor and use that in the second effect, so it's going to
go in to, again this coil for heat exchange, and condense as a liquid, and we can continue
to explain this type of behavior with the flow streams.
So taking advantage of color gives us a significant advantage and introducing the material one
step at a time and explaining what that is has a big advantage over everything at once.
It also helps us to reduce cognitive overload, and what we mean by that is it can be more
difficult for someone learning new material to have this kind of diagram in one place
and then on the next page the text that describes the diagram.
So in a screencast there's some significant advantage to instead introduce the diagram
and explain it in narration and not write down everything that I when I am describing
the diagram because the cognitive overload of having the text and visual diagram together
can make it more difficult for students to learn.
One of the other advantages is that we don't have to be linear in our presentation.
So we can do something and then go back and directly refer to something that we did earlier.
This is certainly more difficult in a textbook without reproducing figures multiple times
and likewise in a textbook the one diagram is presented because if, instead twenty-three
diagrams were presented showing sequential steps it would take up much more room.
So in flow diagram and, for example, a McCabe-Thiele explanation introducing one line at a time
has some significant advantage for making it easier to understand what's being presented.
Of course one of the other advantages of screencasts is that they're short and so we'll finish
this screencast here to keep it short and focused on just a few aspects of screencast
advantages.