bad teachers.. or should that be engineers!

•March 27, 2011 • 2 Comments

Make no mistakes, teaching is a hard profession, particularly when there is a chance that some in the class don’t want to learn.

Degree level, should be easier and postgraduate even easier as there should be filtering to ensure the class contains people who want to be there and more importantly have paid to be there!

I’ve recently been asked to review a MSc in acoustics both in terms of course content and teaching and report back to the endorsing body, what I saw annoyed me & resulted in me having a stand up argument with the tutor.

The issue which caused this was reverberation time, a fundamental of any acoustics course. There are many formulas for calculating the reverberation time of a space, depending on how complex you wish the model to be, but they are all based on some very good work by sabine at Harvard university.

Sabines basic formula for predicting reverb time was based on empirical measurements but cam be explained by a theoretical understanding of Browning motion and is given by:

RT60 = 0.16 V/A

Where V is the volume of the space and A is the absorption in the space

A = s1a1 + s2a2 + … snan

Where s is the absorption coefficient of the material and a is the area of the material.

The absorption coefficient is a boundry coefficient where 0 is a perfect reflector and 1 is a perfect absorper, corresponding to free space (no boundary)

What caused the issue was that the lecturer insisted it was possible to buy a product that will lower the RT60 of the room by having an absorption coefficient greater than one.

It is! And I know of plenty of examples I can buy.

However I queried this with him because with a basic grasp of physics this allows the conservation of energy to be defied… not something I expect a teacher to be teaching!

The situation arrives because the way we engineers have allowed a loophole in the measurement technique; this technique means it is perfectly possible to buy something that defies the fundamentals of physics.

The teacher believes his students wouldn’t understand that, I remember being taught various models of atoms and being told with each “this is incorrect, it goes beyond this but you couldn’t comprehend it yet, this model gets you past this level & if you want to know more take the next level”

if the teachers opinion is true I don’t believe his pupils should be classified as engineers, but the question is …

Should I be more annoyed at the teacher who I gave a fair chance to clarify his statement and I believe was teaching dangerous ideas or at the standards bodies for allowing & refusing to close an obvious loophole?

My Worst Class

•March 17, 2011 • Leave a Comment

Well my friends (I hope they don’t mind me calling them that) over at have been posting about their worst classes ever this week, if you haven’t been to the site STOP reading this and check out their posts, they’re way better at this than me!

My worst class, probably is one I’m not describing here but my comments on the piece by Cherish made me think of this class.  My choice is an electromagnetics course, this it appears is a common theme amongst us engineers, and similar to Chris Gammells post, RF and EM became my career for a number of years so I really shouldn’t have been bad at it.

The course in question introduced us to Maxwells equations & their uses, weeks and weeks of standard engineering problems, forces on a charge between parallel plate capacitors, etc, etc

Fine, Maxwells not pleasant & its only in the years that have passed that I’ve really began to appreciate & get to grasps with his work but on my coursework I did OK, well, lower end of OK but still OK, middle of the table OK and the course itself was interesting (if difficult) for someone who is not naturally gifted at Maths.

When it came to the exam I ended up in the upper percentile of the group, thats great, so why, I hear you ask am I saying this is my worst class?

Answering that requires a bit more knowledge of the course, the paper was multiple choice meaning that you needed to answer four questions from a choice of eight in two hours, when I looked at the paper I couldn’t answer any of the questions, nothing looked familiar or even close to what we’d covered.

I figured I could take a blind stab at all of the questions or I could go down fighting, I answered one question & only one question, but I put every inch of grey cells I could muster into that question, knowing that by answering one question with a possible 25% of marks I’d fail & have to re-sit.. but I’d do it with pride, holding my head up high!

When we came out we mustered into a group to discuss our prospects, even the smart kids thought it was impossibly hard & looking back today I still think answering four questions of that type in two hours was impossible without a priori knowledge.

When the results were posted I came out with 67%, one of the highest grades, I’ll remember that grade to my grave because as I’d answered only 25% of the paper it was impossible for me to have got that grade.  Fortunately for me the university graded on a curve, that is to say it was impossible for everyone to fail the course, a certain number of people had to fall into certain percentile.  The reason why I rate this as my worst course is because the grade is still bittersweet to me today, I never felt like I truly deserved it and I hated every confused minute I spent trying to doing complex maths and ideas to get a murky, cloudy pass.

Being arrogant, headstrong and young, thirty of us, successes and failures alike, all with gruges piled into a very small lecturers room to complain about the hardness of the exam and particularly the annoyance we’d felt at being presented with new problems that we’d never seen before.

I believe his reply will stay with me forever.

“Every year I have this conversation & every year I give the same answer. You all want to be engineers? Do you all think you’re gonna get paid just for plugging numbers into formulas and living off of predetermined problems? If any of you do come back & see me in twenty years and I’ll rethink how I do things, till then I’ve taught some of you a hard lesson that you may not want to face”

I’ve not been back and everything I’ve done so far makes me think I won’t be….