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Dec 21, 2000
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my previous essay I touched on electronics, so I thought that
my second essay should maybe discuss some of the issues that
relate to electronics and education. It must be remembered
that these are my own personal thoughts and obviously they
might not reflect the feeling of my own institution, but as
an academic I feel it is important to express a viewpoint
on this subject. It should also be noted that I have recently
moved from an electronic department to a computing department,
so I've seen computing from both sides of the fence (sorry,
for using a metaphor, but I think that a fence is a good description
of the divide that can exist between computing
departments and engineering
departments.
So what's the problem:
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Your observations are remarkably easy to
relate to, both in this essay and in others -
which makes them strangely entertaining...
Having sat through four years of electronics
and communications engineering, the part about
asking an engineer what a volt is, sent a disconcertingly
noticeable shock straight through me.
Could I explain to someone who is not from an
electrical background the definition of a volt?
More worryingly, could I explain it to an electronic
academic? Mmm, perhaps I could, after some umms,
errs and coughs... I figure, like you mention,
fundamental stuff like this is underemphasised.
That said, we ought to bear in mind that students
should pick up skills and knowledge at uni which
make them useful "tools" in the workplace
- their likely destination. Elaborating the ins
and outs of fundamental electronics might well
set a stronger foundation from which to learn
more, but it will hardly benefit the profit-driven
companies that surround us.
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Comment
on this essay, Wed 06/06/2001 11:05 PM
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IT'S SO BORING.
 Well,
actually, it's not boring. It's just
the way that it's sometimes taught. I'm sure that if
we could actually see the electrical current flowing
in electronic circuits we would all see how beautiful
the electronics actually are. It's a beautifully orchestrated
movement, which has all the perfection of some of the
great works of art in the world. The pulses of light
make 1's and 0's, and the 1's and 0's make bytes and
words, and the bytes and words make up commands and
data, and the commands and data make up logical programs,
which in turn make up operations and procedures, which
perform the required function. Oh, and it's not just
one function, it can be lots of functions for different
people over large geographical areas. Maybe the problem
is that technologists have never really been taught
about how they describe their black magic to others,
who do not understand the TLA (three letter acronyms
- oops, that's one itself) or the jargon (but that's
for another essay).
Isn't it amazing
how a computer works? How the data flows as electrical
signals around a computer and how it all manages to
operate so fast? Isn't it unbelievable how the Internet
works, and how two computers can speak to each other
in different parts of the world, in a fraction of a
second? Isn't it amazing how I can get hundreds of my
favouriate songs onto a CD, which, in the past could
only take a dozen or so? In fact isn't it amazing how
a CD-ROM works? Isn't it amazing how they can fit 10
million transistors onto a piece of silicon, and then
ma ke
it work like a processor? Yes. You agree? The beauty
of electronics and computing has been lost somewhere.
Perhaps it's because more and more material was added
to the syllabus, and the interesting bits fell off.
All the stuff related to audio, video, satellites, and
so on, where replaced with nMOS transistors, digital
signal processing (DSP) and Boolean logic. The other
mistake is that many lecturers think that it's important
to go into a lecture and basically regurgitate the material
that they have just handed-out to them. What's the point
of that? Students can read, can't they? If you watch
some of the best presenters they never go into detail,
but cover the main principles of what they are trying
to present. If someone is more interested in the technicalities
then they can read more, in their own time. I've watched
many excellent presentations go rapidly downhill once
they start to talk about the technical detail of a subject.
I tend to use an ancient America Indian (and possibly
Scottish) technique called a AW WaH a
Coo technique (Pat. Pending), which involves:
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AIMS.
What's the aim of the lecture, and how does it
fit into what we have previous covered? I'm a
great believer of presenting a fully-developed
teaching schedule so that everyone knows the topics
that are covered, each week. |
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WHAT. What's
the concept? |
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WHY.
Why use it? What are the advantages/disadvantages
of it? How does it compare with other similar
techniques? |
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HOW. How does
it operate? |
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CONCLUDE.
Conclusions on the techniques, and how it will
fit into the next lecture. |
The Why and How can be interchanged, depending on whether
you have to explain the operation of something before
you appraise why you would you it.
It is reckoned that less than 30% of the material covered
in a lecture is actually learnt from the lecture situation,
so if possible, the amount that covered should be the
important areas, the rest can be learnt in the students'
own time (typically just before the final examination).
No-one can really learn the detailed operation of something
if they do not already have an understanding about principles
of the subject, and why they actually doing it (of course,
apart from getting a qualification, which is implied).
A lecturer must, of course, assess whether it is better
that a student should remember that it is important
to remember the exact equation for the flow of electrons
in a semiconductor, or whether they are more interested
in the concept of electronic flow.
 Over
the years I have tried to introduce a few modules which
were intended to make things a bit more interesting,
and also stimulating. One had a very bland name (Advanced
Data Communications), but in it I used to teach the
principles of real-time compression for images (JPEG/GIF),
video (MPEG) and audio (MP-3) and also for general compression
(ZIP, and so on). I also included a whole section on
PAL, SECAM and NSTC, as much these are important areas
to consider when design TV equipment. The students,
as far as I could tell, really liked the subject, as
it was teaching them new and interesting areas in electronics.
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Going from
my experience, I often wonder what exactly students
will be learning in electronics in ten years time.
What with component densities becoming increasingly
higher, the printed circuit board (or more recently,
the Interconnect Platform) will host nothing but
extremely complex ASICs and MCMs, not to mention
other, newer IC innovations. These things are
almost entirely designed with CAD tools. Then
they're tested with CAD tools. The so-called engineering
is more like entering-a-specification-into-software.
Can a student possibly be brought up to speed
with this level of complexity in four years? I
figure that if the answer is yes, then no they
cannot define a volt - to them it's a number typically
between 3 and 12. For those that can, lengthy
in-job training is inevitable, because quite simply,
industry is moving too quickly for education.
PS. Great site, Bill. Tons of great stuff to
wade through. |
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Comment
on this essay, Wed 06/06/2001 11:05 PM (cont.)
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IS IT PRINCIPLES OR IS IT HARD SUMS?
Electronics has moved on in the past decade or so. At
one time it was important to calculate all the parameters
of a circuit, whether it be a digital or an analogue
one. But not anymore, we now have computer packages
that can predict these for us, using better models than
we could ever use. So why is it that academics go into
lecture halls and talk about the doping levels of a
n-channel MOSFET device, and then get the student to
calculate the electron drift. Who cares? Who's ever
going to use it? Maybe a designer who's computer has
broken down, and he's got to do a rough calculation.
Ah, but you say, it's the principles that we're teaching.
Ah, but it's not. The main objective is to understand
the principles of Maxwell's equations
, in English, and they relate to the propagation of
an electromagnetic wave, and not how to calculate the
intensity of the E-field at any point in space. The
best test of whether you're teaching the principles
or just using hard sums to try and explain the principle
to someone, who is smart, but doesn't have a background
in your subject. If they understand what you're trying
to teach, then you've succeeded. I reckon that most
of the time academics just use mathematics to make something
more difficult than what it is, and are avoiding the
difficult questions about what is really happening.
As External Examiner you can really see the weaknesses.
Ask a student about the  equation
for the gain of an amplifier and they'll recite it to
you parrot-fashion, but then ask then about what really
happens when the thing starts up and moves into its
final state, and they're stuck.
In fact, a good test is to ask an electrical engineer
what a volt is, and if they say that it's  charge
divided by capacitance, then ask them what charge is
and what capacitance is, and they'll tell you that charge
is change in current over time, and so on, and so on.
Then, in the end, ask them again what is volt really
is.
Here's a few tests if you know any academics in these
areas:
| Analogue electronics |
So how does a transistor
amplify power, and where does the additional power
come from? Why can you call it power amplification
when power is actually lost (in heat, and other
things)? |
| Electromagnetics |
So how does an electromagnetic
wave really propagate? Does it bounce of the window,
and does it go though me? And why do some waves
go through me, but others go round me? What's
the difference between a magnetic field, and an
electric field? |
| Electrical engineering |
Why do birds not get
electrocuted when they sit on a power line? Why
is it more efficient to pulse power in a power
supply (switched-mode power supply) than it is
to use a conventional method? |
| Computing |
How do objects make
it easier to design programs? How does software
actually talk to the hardware? |
| Microprocessor |
What really happens
when I press the PRINT key on my keyboard? |
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When I started out in electronics, in 1977, things were
quite interesting. You could actually see the transistors,
and you could understand what went on inside the integrated
circuits, as there were really just a few transistors which
made up a certain logic function. Over the years, though,
the actual operating of what goes on inside a device has become
hidden.
NEXT ESSAY: Jargon
and TLAs. Do you get mixed up with your FTP's and
your PAM's, why don't worry, it's all just jargon really.
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