Computing At School (CAS) London Conference 2020

24 hours have passed since my third CAS London conference, so here is a write-up. This is my second time presenting at the CAS London conference. You can find my slides from last year’s session on secondary pedagogy here.

The organisation leading in to the 2020 event was incredible, Jane Waite and Jo Brodie clearly sacrificed a lot to put together such a smooth and successful event. The more seamless the event, the more well-organised it is. You never seem to notice when things don’t do wrong!

I was escorted to my room on arrival which was already set up. I quickly loaded my slides, checked everything was working and went back downstairs to catch up with friends and fellow teachers from the CAS network. I spoke to one of my seniors from the Teach First programme, Peter Kemp who is currently in charge of the ITT course at Kings’ College London. We chatted about our open source projects Pete’s A-Level WikiBooks and my Little Book of Algorithms and Computer Science Colouring Book (sneak preview below).

I also got chatting to Rochelle Laurencin from ScreenSkills. ScreenSkills support Peter Kemp’s 3DAmi animation school and it was fascinating to hear of all the work they do, from their bursaries for courses to their apprenticeships. I have a student who does not want to go to university and wants to go into the film industry, so we exchanged details and I picked up some flyers and posters to share when I returned to school.

The Keynote was by John Nixon. He’s an HMI (one of Her Majesty's Inspectors) and Ofsted's National Lead for Computing and Online Safety. I wasn’t expecting to take so many notes. However, with the new inspection framework, I found myself scribbling away furiously and I realised that the four pages I filled, was the most amount of notes compared to any of the other sessions on the day. His keynote deserves its own separate blog post.

I figured that a lecture theatre operates very much like a stack data structure, last in first out (LIFO), so I made sure I was at the end of the second row and made a speedy exit to get to my session. My session was about one dimension from Legitimation Code Theory – Semantics. I hoped to introduce attendees to Semantic Waves and how they could apply some of the associated principles immediately on their return to school on Monday. I started out by looking at the big picture of classroom best practice and then considered the role of Semantic Waves in our practice.

Perhaps Semantic Waves are a missing piece of the infinite and addictive puzzle that we also call “teaching”.

A bold claim.

We looked at the theory and went through some practical tasks, along with a sample lesson. All of these resources are available here.

In choosing sessions for a conference, I have a few parameters that go into my so called selection algorithm:

1. Have I attended the session before?
2. How good is the speaker? – What is their background? Do they have a proven track record? How good were their previous sessions?
3. Can I make use of their workshop in the next week, day, month or year?

Based on criteria 1, I therefore automatically de-selected Sue Sentance’s and Peter Kemp’s sessions on PRIMM, Programming with Python and Flask and 3DAmi. All excellent sessions which I chose based on criteria 2 and 3 at previous conferences. The three remaining sessions, I must admit I went by the presenter’s reputation first. I chose:

• Hardip Mothada’s session on Stacks using Forth
• Paul Curzon’s session on Semantic Waves
• Katie Vandepere-Brown’s session on the Fetch Execute Cycle

I was not disappointed. I left trying to pick a favourite session and at first I thought it was Hardip’s, but then I couldn’t put it above either Paul’s or Katie’s. So why were these sessions chosen and why do they all receive a resounding 5-star review from me?

Hardip is a rare gem in that he currently teaches both OCR and AQA A-Level Computer Science. He taught himself how to write computer games on the Commodore 64 in the 80’s and his understanding and ability to break down and deliver complex concepts will leave you in awe. His session used a programming language called Forth. Hardip told us that Forth is a programming language, an IDE and a philosophy too (woah, mind blow already). He reeled us in further by telling us Forth was used to write programs for robotic arms on the International Space Station and some of these programs are less than 4kb! The language is clearly robust and it is entirely stack based which make it wonderful for teaching and learning stacks. Despite not using Forth for 30 years, Hardip demonstrated fluency whilst also pacing us gently through the exercises, which were all of course mapped to AQA and OCR spec points. I chose this session based on Hardip’s reputation and I was not disappointed. I left feeling as though I’d just been given the cheat code to teaching stacks. How had I not realised the sequencing and thought about using a stack-based language sooner? His iterative approach, re-visiting how stacks are used was a key theme throughout the conference. Thanks Hardip. You’re incredible. If you’re reading this wondering how you can find out more about Hardip or whether he might be able to help your school, he does outreach work as he is currently part time. So if you require some training or 6-12 week development/teaching particularly at A-Level standard, you can email Hardip at HardipmATgmailDOTcom.

Lunch was great as usual. I recalled that at my last visit to Gladesmore Community School (GCS) I was impressed by the facilities and I must say, my return left me thinking it really is a brilliant venue with great staff and students. Between Igli and his team at GCS and Jane and Jo’s CAS London team, it sets a high standard for other conferences. The conference’s 200 tickers were sold out and 80+ were on the waiting list. The success of this conference made me think back to the CSTA conference – an international conference that I attended in Baltimore in 2017. I wouldn’t be exaggerating if I said that I think we could host something of similar scale in the UK – 1 week of Computing CPD in the summer or Easter holidays. I’ve got so much faith in Jo, Jane and her team. I don’t know if the CAS National Conference will make a return or not, but I can envision an international conference within the next 5 years in the UK. We definitely have the quality in terms of workshop /session facilitators. It was clear that many of the sessions on Saturday could have lasted 90 mins or even 2 hours. A format that the CSTA conference sometimes uses, allowing for 3 sessions in a day over the week. It's something worth thinking about…

Back to the sessions. Session 3 was a somewhat unusual choice for me. My session was entitled, "Going from abstract to concrete and back again with Semantic Waves" so why did I also attend Paul Curzon’s session entitled "Semantic Waves"? In the run-up, Jane expressed slight frustration that I had chosen to deliver a session with the same focus as Paul’s. However, having attended both, I can assure her now that attendees would have got something different from both sessions and it was totally worth it. I chose Paul’s session for several reasons. I’ve been attending Paul’s training sessions since I first started teaching in 2006; he’s been running sessions at Queen Mary University London (QMUL) often with William Marsh and Jo Brodie – quite possibly they were doing this before the existence of CAS. I always leave those sessions thinking Paul is a crazy genius (in the nicest possible way) and that I could never deliver or teach like he does. This is exactly the reason why I keep coming back. Paul recently won the IEEE Computer Society 2020 Taylor L. Booth Education Award. The previous link goes into a some detail about Paul’s contributions to computing education. However, his attitude and work rate were exemplified by the fact that he delivered four sessions on Saturday (including a lunchtime one!). I just about had enough head space to run one session and deliver a TeachMeet presentation. Paul clearly operates on another level. He is a seasoned professional on the conference and CPD circuit.

The most important takeaways from Paul’s LCT Semantic Waves session was firstly that Semantic Waves can be used to evaluate lessons and lesson planning. His clear division of disciplines into technical language and abstract concepts was also powerful. Lastly, I left with the important differentiation between a teacher planning Semantic Waves in their lesson activities and students actually doing the repacking themselves and riding the wave themselves.

Yes, you may be teaching…but what are the students doing and what are they thinking about?

This emphasis on the students doing the repacking, not just the teacher was such a simple point, but it is an important lever in working with Semantic Waves. We had different foci and emphasis in our sessions and I left feeling even more informed. Of course, I also got to witness some signature unplugged teaching activities from Paul too.

The fourth session was with Katie Vanderpere-Brown. Katie is a regular contributor on the weekly #CASChat on Twitter (Every Tues at 8pm). I signed up to Katie’s session based on our similar views on computing education, our interest in cognitive science and our skepticism towards some online learning platforms. We met briefly over lunch and when someone tells you that they’ve come up with a way to print onto post-it notes, you realise that you’re talking to someone who is serious about their teaching craft or someone who is addicted to stationary or both. Katie is both.

There’s a few people who have debated with me about the importance of passion and enthusiasm in teacher delivery style. A prolific tweeter once proclaimed that it just wasn’t their style and enthusiasm and passion were not important-you just need knowledge and good behaviour management. I have to disagree! I think I can spot a good teacher within 30 seconds of watching them teach. This sounds arrogant, but I’m quite confident in my “thin slicing” after developing and observing (probably over fifty) teachers over the years. One of the things I subconsciously notice very quickly is whether or not the teacher wants to be there-how passionate are they about the subject and the lesson they are teaching? Would I want to be taught by this teacher? Within ten seconds, Katie passed this test. Her relaxed and humble demeanor, enthusiasm and informed delivery puts you at ease. After a minute, it felt like I was sitting at home catching up with an old friend. Except, this was someone I’d never met before. Katie went through three different ways of teaching the fetch-execute cycle and I have no doubt that if you ask any of her students, they could tell you the name and function of the registers and memory during the CPU’s fetch execute cycle. The first activity was a card sort with printed post it notes, the second an unplugged physical activity and then she consolidated by demonstrating how we could use different LMC simulators. We were her guinea pigs for some NCCE/Isaac Computer Science material and I think we all left pretty impressed, particularly given that she was weaving metacognitive theory in between her tasks.

The first task with post it notes, simple as it was, generated a lot of debate about sequencing. It made us all think about what the pre-requisite knowledge was for teaching the fetch execute cycle. The three simulators that we saw: 101 Computing , Peter Higginson’s new RISC LMC and Higginson’s AQA LMC  were all new to me. I'd grown so used to the original LMC, I had not really invested the time into exploring the new versions and I have to admit, the 101Computing one is my favourite.




Whilst the physical unplugged task which demonstrated the use of cache memory would be difficult for me to implement in my computer suite, I could see how it would work if we had a different room layout. It is a lovely idea and clearly shows how some instructions in cache clearly have a faster access time. The misconception we need to be careful of here is the student's discussion of distance. Frequently students say that the cache is nearer than the RAM and this is why it is faster. Distance is somewhat insignificant in the fetch execute cycle as electrical signals move so quickly over such short distances. This is something that a lot of students misunderstand. The real focus of the activity should be on the access speed of different memory types and the overall execution time.

After the last session, I managed to catch up with a few old colleagues and friends before delivering my TeachMeet presentation. My TeachMeet presentation was on the importance of language, etymology and storytelling in computing education. My example was on the origins of cache memory and how the term "cache" originates from 18th century French Canadian fur trappers! This presentation was inspired by one of my former head teachers, the great Oli Knight. I hope those that attended will share this story far and wide.

What a day! My thanks go out to Jane, Jo and all the volunteers for ensuring the conference was a success. Thanks to all those who ran workshop sessions and it was good to catch up with some old friends. I hope we can grow this conference into something much bigger with a wider international reach. However, for now I still love the intimacy of our London CAS community conference. Until next time…