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Friendly Handmade Explanation Videos
Jörn Loviscach
Fachhochschule Bielefeld (University of Applied Sciences), Bielefeld, Germany jOERn.loviscach@fh-bielefeld.de
Abstract: MOOCs have further popularized the informal style of handwriting and freehand
sketches that is the hallmark of Salman Khan’s video lessons – a style that enables a unique
combination of concise content, conversational, seemingly effortless presentation, and
inexpensive media production. This paper provides an overview of techniques concerning
the didactics and the visual presentation developed and/or used by the author in almost
five years of creating thousands of such videos in a range of settings from the flipped
classroom to a MOOC, mostly focusing of topics related to mathematics for engineers. This
paper illustrates a number of principles by examples, shares tricks and lessons learned, and
discusses relevant literature on illustration and on learning research.
Key words:
Khan-style videos, visualization, sketching
Aiming too High or too Low
“It has the words DON’T PANIC inscribed in large friendly
letters on its cover.” This outstanding feature of the Hitchhiker’s
Guide to the Galaxy (Adams, 1979) is rarely found
in STEM courses, especially courses in mathe-matics and
physics. Explanations given in such classes often appear
to be hostile rather than friendly, so to speak. For an example
of such an explanation that confuses even people
well trained in mathematics, consider what Wikipedia has
to say about the set (technically called TxM) of vectors
that are tangent to a manifold (which is a generalization
of a curved surface) M at a point x: “Consider the ideal, I,
in C ∞ (M) consisting of all func-tions, ƒ, such that ƒ(x) = 0.
Then I and I 2 are real vector spaces, and TxM may be defined
as the dual space of the quotient space I/I 2 .” (Wikipedia,
2013) This is exact and concise and may therefore be
appropriate for an ency-clopedia, but it does not provide
any intuition on what happens here, particularly in terms
of geometry, even though tangent vectors are supposedly
highly geometrical objects. Students of engineering or
physics tend to be put off by such explanations and demand
more vivid presentations. They want to know about
the Why and the How. In earlier times, students may have
been expected to start from such an abstract presentation
and work out the intuitive meaning on their own – which
is a valuable exercise, if the students actually accomplish it
and don’t give up on the way.
Although abstract formal definitions and derivations
may be of little value for learning or may even appear
frustrating, they are still explanations. Another mistake
is to present recipes rather than explanations: “The cross
product of two vectors is defined as follows: …” with no
hint of an idea where the given equation comes from and
why such a mathematical construct makes any sense at
all. This teaching style fosters shallow learning and makes
students mindlessly plug values into formulas, as they
hardly know anything else about those formulas.
Textbooks, as well as lectures, succumb to both mistakes:
intimidating abstraction as well as shallow recipes.
A third type of issue can be seen in popular science, in particular
in television programs: Aiming to at-tract a broad
audience (As many MOOCs do nowadays), such programs
tend to suffer from oversimplification and, hence,
pseudo-explanations. For example, consider the Higgs
boson confirmed at CERN in 2012. In popu-lar media, its
particle field is described as “cosmic molasses”. A motion
in molasses would, however, cause a particle to continuously
lose speed, which is in contrast to the behavior of
elementary particles. (For a discussion of real-world analogies
for the Higgs boson, see Alsop & Beale, 2013).
The New Style of Educational Videos
The advent of user-produced educational videos has
opened the floor to new visual and didactic styles, as exem-plified
by Salman Khan’s success (Khan, 2012) with
screen recordings of electronic scribbles resembling a
blackboard, accompanied by his voice but no visible face.
Publishing houses and some universities are refrain-ing
from such a handmade, informal and possibly “cheap” look.
Yet MOOC providers – in particular Udacity – have made
it a central element. This visual style is a key enabler for
concise, easy-to-grasp explanations that look (and often
actually are) improvised. It would seem odd to see such
explanations as printed texts or as high-ly prepared PowerPoint
presentations. Many providers of remedial instruction
have also adopted this visual style, even though
in these cases, it tends to focus on recipes rather than on
explanations.
Experience Track |240