Friday, May 31, 2019

How YouTube support videos are used as part of cramming for exams - Presentation Slides #edtechIE19

I enjoyed presenting at EdTech 2019 in Dundalk IT yesterday - it must be one of the friendliest conferences going! Here is a copy of my slide presentation and abtract:


Cramming for exams is a widespread phenomenon where students study almost non-stop just before an exam that’s coming up, but that they haven’t prepared fully for. This traditionally involves going through notes which are either provided by a teacher/instructor, or taken by the students themselves. Cramming is the opposite of the “Spacing Effect” which states that studied material spaced out over time will be remembered better when compared to when material is crammed together. While educators agree that cramming in a poor strategy for learning, it is still a strategy employed by many students. With the arrival of video websites, such as YouTube in 2005, there are many opportunities for modern day students to learn from short videos created by content developers for this purpose.

In this study, data for views, audience retention, and durations of on-line videos provided as support for Statistics modules are examined. The data show stark evidence of intense last-minute study where key videos are viewed in the 48-hour period before a scheduled exam takes place. Almost no views are recorded for the support videos throughout the semester or in the aftermath of an exam. Individual videos are linked to specific exam questions to show the cramming effect. Audience retention and average duration in the 48-hour period before an exam are compared with retention and duration outside this period. Overall, the results clearly indicate that on-line support videos are now part of the cramming phenomenon. No evidence of the spacing effect was found.

Thursday, May 23, 2019

Accents - Be Proud of Yours

I read with interest a recent post on Linkedin by Irene Contreras: "I DO have a foreign accent, so what?". Irene is from Venezuela but lives in USA and writes that she told that she had "a strong accent" so she started to "conceal it". She further writes that the results were "catastrophic" and that trying to hide her accent "wasn’t the solution; that became a new problem".

There's no doubt that we all have an accent! In Ireland we can tell which of our 32 counties a person comes from after hearing just one or two sentences - I'm sure it is the same all over the world. Some people are very self conscious about their accent and try to posh it up a bit. Most of us don't bother. 

I have been living on the south side (posh me?) since 1986. I was born and raised in South Co Wicklow near the Co Wexford border, and when I hear my own voice in recordings, I always think I sound like somebody who is from South Co Wicklow near the Co Wexford border. Apparently not - my family tell me that I am soooooo South Dublin with my accent! A bit of a mix I guess is what I have.

Many of my YouTube Channel viewers leave comments - mostly asking questions and thanking me for posting the video. I do get some negative comments, and very often these are related to my accent:
  • omg your accent is so annoying
  • shame about the accent, thumbs up if you agree
  • I really hate this guy's accent
I also get some nice comments on my accent:
  • Are you from Ireland? Nice accent
  • Came for the content, stayed for the accent
  • The accent is everything man
  • Thanks! Your accent made this even more fun to listen to
  • really enjoy Eugene's Irish accent. It makes learning fun again :D
You can't please everybody!

Thursday, May 16, 2019

Should students be forced to make presentations for assessment?

Image source: Clipart Library.
At this time or year many students are presenting their research results as part of their assessments. For many it is a traumatising experience - I regularly have nervous students in front of me who are terrified of losing marks. We are often told that fear of public speaking is one of the most common of all phobias - yet we (academia) insist on putting students through this experience/torture. And then we grade them!

Anna Fazackerley, writing in The Guardian, asks the question about public speaking: "is the push to make students employable going too far?". Employers often emphasise the importance of communication skills, and it is good to be able to present to colleagues, management, and clients in the work environment. But what about students who suffer from anxiety or other mental conditions - is if fair to force students to present? Mark Twain is quoted as having said: “There are two types of speakers: Those who get nervous and those who are liars”. I think it is fair to say that we all get nervous when presenting. Some people are naturally confident, while others do it for a living (eg - Lecturers such as me). Forcing students to present even for 5 minutes can be daunting - most in my experience get through it and I always try my best to get students to be as relaxed as possible.

Fazackerley, in her Guardian article, writes about efforts at Bristol University to offer "presentation coaching, starting with small exercises and building confidence until students feel they can tackle a whole presentation, and that to begin with, "students practise public speaking as part of a group". Help is available, so students should consider this if they are faced with the prospect of a presentation that they are anxious or worried about. 

Monday, May 13, 2019

"Absolute Confidence" # Statistics #Analytics

Tim Healy writes in The Irish Independent that a US laboratory confirms it will appeal landmark judgement in Ruth Morrissey cervical cancer case. I have no argument with the results of the case or the award made by the court - my comment here is based on statistical probability. However, an intriguing aspect of the judgement is that the Judge ruled that laboratories should have "absolute confidence" in their results.

Is there such a thing as "absolute confidence"? Well - yes, there is. We will all die, night follows day, and so on. But could there be "absolute confidence" in smear or any other tests? The answer is theoretically "Yes", but practically "No". The reason is that in statistics, we make inferences about populations using samples (think of a poll before an election). For example, we accept that Paracetamol is an effective cure for pain in humans - but does it work in all cases for all humans? We can't know that unless we test every single person in the world - an expensive and impractical idea. All we can do is conduct clinical trials on a sample of the population and make inferences about the population using the results. Because it is a sample, we cannot be certain of the result - hence there is always uncertainty in experiments that do not involve the entire population. What we can say is that we are confident of the result - 95% or 99% confidence is often an acceptable level of confidence in statistics.

Without wishing to diminish the awful cases that some people have endured due to misread results, there is uncertainty in almost everything that we do. In 2018, 149  people lost their lives on Ireland's roads - there is a risk that you will die every time you use our roads. Thankfully, this is a small risk - 149 deaths from a population of 4,857,000 (Estimate: April 2018, CSO) - this translates into a 0.003% chance of being killed on our roads. While this is a tiny risk, it does mean that our roads are not safe for everyone. A 0.003% of being killed also means that you have a 99.997% of not being killed.

Is 99% confidence enough? Would you get on a plane if you were 99% certain that it would not crash? According to FlightAware, there is an average of "9,728 planes, carrying 1,270,406 people, in the sky at any given time". If 99% of these were safe, this means that 9,631 would be safe - but 97 would not be safe. That's a lot! What about 99.9% safety? 9,718 would be safe, but 10 would be unsafe. Only at 99.9999% would you get an acceptable safety level - 9,727.99 out of 9,728 flights would be safe. Still a tiny chance, but enough for us to get on a plane. Crucially, even at 99.9999% we cannot have "absolute confidence".

Tuesday, May 07, 2019

A blast-from-the-past

Out of the blue today I received a link to an old video in which I featured but had never seen. In my previous job at CBT Systems/SmartForce in the late 1990s, I was a Product Manager and my first big job was to manage the creation of a suite of Novell Certification courses (then only available on CD-ROM or floppy diskettes). One of the courses was "NDS Design (532)" and I was sent to Provo in Utah to participate in this course delivered by Bob King (who put the video on YouTube last month and sent me the link). It was a three day course and a camera crew came in to the Novell offices to shoot some footage to promote the new course. I had completely forgotten about this. I'm guessing this was done in 1996 - at the time the company was called CBT Systems (which in turn became SmartForce in 1999). I am even seen wearing a CBT Systems t-shirt in the video, and of course I look a lot younger then than I do now.

Here's the video, I am featured at 3:36, 4:45, and 6:05

Thursday, May 02, 2019

How many toilets do you need in a Theatre? #MoreLoos #LittlesLaw

Joanna Lumley.
Image source: Irish Independent.
I read with interest an article by Sinéad Ryan in yesterday's Irish Independent: "Biggest drama in theatre is getting to loos". She had attended an event in a community hall where there were "just two cubicles for a room holding 300 people". As a man I have had rarely needed to queue to use the loo in places such as theatres, arenas, or public places - there is a definite anatomical advantage to being male when it comes to time for a pee. "Joanna Lumley won’t take shortage of ladies’ loos sitting down" writes Rebecca Nicholson in The Guardian newspaper - the lovely Joanna has launched a "More Loos" campaign and says that the "ladies are about to storm the men’s loos. They can’t manage to have a drink and a waz at half time"! In her article, Sinéad Ryan uses our own Abbey Theatre which has been criticised recently for its lack of loos for women. 

So how many loos are needed to satisfy demand?

Prof John Little.
Image source: MIT Sloan.
Fortunately, there is a formula for working these things out. In 1961, Professor John Little of MIT published what became to be known as Little's Law. This law illustrates the mathematical relationship between throughput, work-in-progress (WIP), and cycle time. Let's use Dublin's Abbey Theatre as an example to work out how many toilets for women are needed during a 20 minute interval in the middle of a show.

The capacity of the Abbey Theatre is currently 492 seats - let's assume for simplicity that at a typical performance that 50% of the attendance are female. This means that there would be 246 women at each performance. This is our WIP (demand for toilets). The throughput is the length of the interval time - in this case 20 minutes. Finally, let's assume that on average, each woman spends 3 minutes in the toilet cubicle, and that there are 10 cubicles available (I don't know exact figure as I have never been in the ladies' toilets in the Abbey!).

In summary:

    WIP (Demand for toilets) = 246 women
    Throughput time = 20 minutes
    Work content = 3 minutes

First - we need to calculate the cycle time:

        Cycle time = Throughput = 20 = 0.08 minutes
                    WIP      246

Next - calculate the number of toilets required :

        # toilets required = Work content = 37.5 toilets
                         Cycle Time    0.08

There are not enough toilets to deal with demand since as 37.5 (say 38) are required. Given that the work content (the time taken to use the loo) cannot realistically be shortened, nor WIP (demand for the loo) be reduced, then what are the options?

  1. More toilets - 38 to cover demand
  2. A longer interval:
     (New) cycle time = Work content = 0.3
                         # toilets     10

Throughput time = WIP x Cycle time = 246 x 0.03 = 73.8 minutes. The interval would need to be 74 minutes long to ensure that all demand was met.

Wednesday, May 01, 2019

Why don't An Post use eircode?

I took a delivery this morning from An Post for a new book purchased from Amazon - I'm delighted that they use our national postal service to deliver our parcels. No doubt that this is contributing a significant part of An Post's business - see "Profits at An Post surge by 400pc while it closes offices" announced today.

But what really surprised me was that the delivery man called me from his phone as he approached our street - I could see him through our front window. I take particular care to ensure that my address is full and accurate - plus I now always add my postcode/eircode. It turned out that the printing on my parcel label was very close to the edge, and the driver could not tell if my house number was "2", or "12", or "22" and so on. I also know that these drivers are under tremendous pressure to deliver quickly, so no doubt he was saving himself some time to avoid checking every house on our street that has a "2" in the address. When he got to my door I asked him could he not have used the eircode (which was on the label)? He said that while it is used in the sorting office it is "no use" to the drivers, and that the drivers "can't find anything" with the eircode. They do not have a navigation system that can use the eircode and bring them directly to the delivery address. They are still relying on the street address, and still have to use the phone if their is any ambiguity on the address label.