COMPUTING AT SCHOOL NEWSLETTER WINTER / SPRING 2012 GOVE’S SUPPORT FOR CELEBRATING THE GENIGENIUSUS OF COMPUTER SCIENCE "Computer Science is a rigorous, fascinating and intellectually challenging subject”. So says Michael Gove, Minister of Education. He continued his “We in Britain should never forget that one of our great heroes, Alan Turing, laid keynote speech at BETT by saying; the foundation stones on which all modern computing rests.” In his BETT “Although individual technologies speech (see right) Michael Gove highlighted 2012 as marking the centenary of change day by day, they are his birth. Some students may be aware of the name, largely because of his underpinned by foundational code breaking activities during WW2. Some may know about the tragic nature concepts and principles that have of his death; a persecution that is hard for many to grasp today, though it endured for decades. Long after happened little more than fifty years ago. today's pupils leave school and enter the workplace - long after the But how many will be able to recount any details of his key ideas? In the technologies they used at school preface to his excellent book, ‘The New Turing Omnibus’, AK Dewdney pays are obsolete - the principles learnt tribute to “...Alan Turing, whose ripe mathematical imagination was fuelled by in Computer Science will still hold fantasies of mechanized intellect. Turing’s greatest single legacy, the Turing true". This is the clearest statement machine itself, became the best known vehicle for the emerging theory of yet from the Government. computability. Wonderfully simple, with only two moving parts, it can be explained to the man or woman in the street, yet it embraces everything we Two days later, The Royal Society mean by the word ‘computable’!” published its 18 month study, “Shutdown or Restart” carefully Turing was a genius ahead of his time, yet few identifying three separate strands pupils are aware of his place in history. that comprise Computing in Computing has been hidden from the schools. They make 11 curriculum for far too long. Many wrongly recommendations to take the equate computing with just learning about subject forward. programming. It’s far deeper than that. You’ll find pointers to Turing’s ideas inside this Michael Gove cited the CAS newsletter and more in the online supplement. Curriculum as one source schools The centenary is a marvellous opportunity for should look to when planning new teachers to resurrect some key computing curricula. CAS look forward to concepts; concepts developed by Turing before an supporting teachers as they plan for electronic computer had even been built. September and beyond. We also We’ll cover some resources in each issue look forward to working with others this year. A wonderful five minute BCS in creating a curriculum that inspires video, made as part of their Pioneers our youngsters with the magic and series, is the perfect starting point. beauty of computer science.

Why not use it for an assembly? image © The Bletchley Park Trust

The “Computing At School” working group (CAS) is a membership association in partnership with BCS, The Chartered Institute for IT and supported by Microsoft, Google and others. It aims to support and promote the teaching of computing in UK schools. THE BLINKING REDISCOVERING THE SPSPIRITIRIT OF CURSOR The 80s were rubbish. We were THE BBC MICRO: promised Bacofoil jumpsuits and teleporting to school. Instead we Even before its launch, the innovative Raspberry Pi is already got Cabbage Patch Kids and gaining widespread acclaim. But how did it come about? In an strikes. Fortunately we also had exclusive interview Clive Beale talks to Liz Upton about what the best thing ever invented: low spurred its development and motivated the trustees. cost home computers that plugged into your telly. The mighty Where did it all start? Was there a work in games – but his family don’t BBC Micro; the po’boy ZX light bulb moment? have a computer. Mum’s a cleaner, Spectrum; the painfully hip There wasn’t a eureka moment; more Dad drives a van. Neither comes into Commodore 64; plus a lesser a growing, horrible realisation that contact with computers in their daily pantheon of Dragons, Orics, things in school computing were not lives and they’re not a necessity in the Lynxes and more. as they should be. Eben (Upton) was house. They have a Wii, which the working at St John’s College, kids use to browse the internet, but a Playground fights over which interviewing kids applying to the Wii is a closed box that no kid is going machine was best were not university. There was a noticeable to be able to program. It’s a story uncommon. Yet these computers drop-off in the quality of applicants. In we’re hearing over and over again. all had something in common: the 1990s, those coming to Cambridge Twenty per cent of UK homes don’t when you switched them on they would arrive equipped with a few have a computer. Since schools just sat there, blinking. Waiting for programming languages and several stopped teaching programming such you to tell them what to do. This years’ experience of hobbyist hacking. kids have no way into computing. was a wonderful thing. The micros By the 2000s, things had changed came with programming manuals significantly. The typical applicant had After an evening complaining, Eben and there was an irresistible urge perhaps written HTML, used CSS or got out some breadboard, ordered an to make them do stuff. So we created a macro or two, but that was Atmel chip and a pile of transistors, hacked and we POKED and we usually the extent of their and sat down to solder together a little coded and created. At least until ‘programming experience’. The computer that booted into Python, with Mum kicked us off the telly numbers applying were falling too. an idea to build a kit that perhaps you because That’s Life was on. could sell to schools. I got to hold the We talked about the causes. A voltmeter. Five years on, one room The blinking cursor single number of factors are in play, but one has been converted into an handedly made the UK tech and big culprit seemed to be the electronics lab, and that first board digital creative industries the envy disappearance of computers which and Broadcom chips have had babies of the world. Never mind that are easy for kids to program. These which turned into Raspberry Pi. Google’s Eric Schmidt recently vanished with the ubiquity of the found our “great computing Windows desktop. We grew up with If I was gathering a team to take heritage” stuffed in a skip round BBC Bs, Amigas and ZX Spectrums. over the computing world, the the back of Poundland. The 8-bit You had to type something to make RasPi Trustees is where I would revolution is what kicked it all off. them do anything. My Beeb, and the start. Apple started with a lot Beebs at school, booted into Basic; less :). How did you get together? The every kid in school knew how to walk Eben brought the team together from wants to reboot this revolution. It into WHSmiths and run a little friends who work at the Cambridge wants to recapture the fun and program making all the display Science Park (David Braben); old excitement and creativity of these machines say “This shop smells of colleagues from the university (Jack early micros; to get kids coding cheese.” (We also knew how to sprint Lang, Alan Mycroft and Rob Mullins) again and to foster a new out of WHSmiths. They called it a and friends of theirs (Pete Lomas). generation of computational rounded education!) Programming They were picked for their experience thinkers and digital creators. was much more prevalent in school; – David is, quite simply, legendary in Its plan? To make a low cost the curriculum has changed to an British computing; Jack worked on home computer that plugs into unrecognisable degree. software for the original BBC Micro your telly. That sits and teaches business; Pete runs a there and I told a neighbour’s kid about PCB fab that’s one of those British blinks at Raspberry Pi. His ears technological success stories; Alan you...... pricked up; he told me how and Rob’s educational contacts and he’d love to learn to program, to experience are as good as you could RASPBERRY PI FOR EDUCATION USER GUIDE An education version of the Pi is planned for release this spring. It was very clear to CAS that a user guide was a must, and with the Raspberry Pi team already Jack Lang demonstrates a prototype Pi at a CAS working group meeting overstretched we decided to write one ourselves. The guide will hope to find. They’re a really strong There are other machines out there teach two languages, Scratch and team, and I think we’d have struggled that do a lot of what Raspberry Pi Python, through creative to put together a group like this does. But we are innovators on cost. scenarios such as music and anywhere outside Silicon Fen. Success would be competitors driving graphics. It will also include advice costs down so they’re accessible to and resources for budding In a project like this, where we rely so everybody. The fact that it’s possible computer scientists. The outline of heavily on the open-source to produce hardware at this sort of the guide is already written and community, transparency and a price, running open-source software, there is currently a huge amount genuine gusto for what you’re doing is exposes how expensive business of work going on backstage to essential. I’m preternaturally software is. When a license is ten develop the content. The guide enthusiastic about the project. I’ve times the cost of the hardware you’re will be available as a free been living with generations of circuit running it on, that’s quite startling. download and we are boards stacked all over my house for investigating the possibility of a years, so I was a good fit for getting Broadcom are instrumental in the printed version. Paradigm shifts the Pi community up and running. project. Is this an experiment, or a are ten a penny nowadays. favour? Do they share the Everything from smart phones to And the name? Is it a riff on Apple? Foundation’s goals? air fresheners are described as Is there a nod to Python? Broadcom sell us chips on commercial “game changers”. But in a couple It’s partly an in-joke. Fruit names terms; they aren’t subsidising us, as of years we may well look back were a nice tradition in computing some people believe. They’re doing and see that the Raspberry Pi (Apple, Apricot, Blackberry, Tangerine us favours in agreeing to sell us chips deserves this sticker. We hope and all that jazz). I think Rob at all, because our volumes are that the CASpberry Pi user guide suggested the raspberry, which is a millions short of what they usually sell will contribute to its success as a friendly fruit – Pi, a reference to in; and in allowing some engineers to learning tool and help inspire a Python, came from Jack, an ex- work on the project in their spare time. new generation of coders. restaurateur and fan of pastry. They believe in our goals; we’ve had support and reassurance right up to and later, jobs in UK tech The original charitable objective is: CEO level. On a purely business level, companies. We can do much more “to further the advancement of ensuring graduates can program is a than that, but the proof of the education ... particularly in the field good thing. They have a very active pudding is in the eating. We would of computers, computer science charitable arm (The Broadcom love to be able to bring more girls and related subjects” Has this Foundation), much more responsible into the subject, but I’m not sure that changed in the last two years? than some of the more opinionated that’s something the Foundation can When the community started to open source community would have address; it needs to be happening in respond to the idea we realised the you believe! That has hooked us up schools, at a classroom level. potential scope was far, far wider. with charities, especially in India, After David appeared on Click Online which we hope can push the device Many people want to change the (BBC, May 2011), we started getting into the developing world. world. Most don’t. Why is thousands of mails a week. Many are Raspberry Pi different? from groups priced out of traditional Jack Lang said, “there’s no point in It’s a mindset thing. I don’t subscribe computing. Suddenly, the impact of inventing a better mousetrap if to the notion that one person can’t what we’re working on started to mice aren’t a problem.” Have you make a difference. You’ve got to be look…a little scary, if I’m totally understood the problem? Is prepared to work hard if you want to honest. We have to get this right. Raspberry Pi the solution? change things – but if you’re working If we reach one kid per school who on something you’re passionate Do you see it as a game changer? has a latent talent we’ll have done about, it’s not really work, just a very Lord, we hope so. We’re not really what we set out to do; reinvigorating supercharged hobby that requires a innovators in size or compute power. the demographic applying to university serious caffeine habit. Clive Beale

SWITCHED ONONON web supplement: www.computingatschool.org.uk SCHOOL PROTOTYPING PILOT GAMEMAKER: A GREAT WAY WITH NEW .NET GADGETEER Microsoft Research have recently released TO LEARN HOW TO PROGRAPROGRAMMMM an exciting new product to enable the prototyping of a huge range of gadgets. Graham Hastings was shown GameMaker by a pupil in Sue Sentance reports on a school pilot his computer club nine years ago. They created that has been running in eight schools in professional looking ‘arcade’ games within a few hours. Essex and Cambridgeshire. He explains the appeal and why he is still using it today.

.NET Gadgeteer was developed by Nic At that time I ran a small Villar and James Scott. The first kits are club for children (aged now available for sale from GHI 11 to 13) who were Electronics. It has great potential in interested in developing schools as it can be used to teach their computer skills. students simple electronics, computer Using GameMaker it is programming and computer-aided design. possible for children as A digital camera can be built in about half young as 7 to program an hour! events using simple, easy-to-learn, drag-and- A school pilot has been running in Essex drop actions. They and Cambridgeshire to find out how amaze themselves and secondary school children get on with the their friends when they programming of the Gadgeteer. Eight successfully create secondary schools are involved. After- professional-looking school clubs were games. Once the planned for Year 9s to children are more An example of a simple GameMaker arcade style treasure game try out the teaching experienced, I encourage them to use the built-in GameMaker Language materials that I am (GML). They can work with existing ‘blocks’ of code or write their own developing. The pilot scripts from scratch. Using GML it is possible to teach all the was launched at a programming constructs children might learn through working with a workshop on October mainstream programming language. 6th. The teachers spent the afternoon building Until I saw GameMaker I tended to teach Visual Basic because the gadgets using .NET children liked to create their own little Windows style, self-contained, Gadgeteer and had the applications. They weren’t keen on the rigour of testing though. With opportunity to talk to the GameMaker, the children are eager to test their creations on their developers about tricky bits of friends and take the comments made by their peers seriously. When programming. The pilot will end with a developing games the performance of their application is a major grand “Show and Tell” at Microsoft concern It is particularly rewarding to see how eager they are to amend Research on January 30th 2012 where all their games in light of the advice received. The children display a participating children will be able to competitive edge. They want their game to be the ‘coolest’ and become demonstrate the gadgets they have involved in a race to develop them. They are, in short, fully engaged developed themselves with the best being with the design process. awarded prizes. Teaching GameMaker requires little prior knowledge. There are oodles The after-school clubs are well underway. of tutorials and lots of guides posted on YouTube (many by children). There have been no shortage of children YoYo Games has developed an extensive, active and supportive wanting to take part. Niki Smith, a community. It serves as a space for children to seek help and download participating teacher says of her club “the games and tutorials – everything a teacher could wish for. Moreover it children are having a lovely time with teaches them to learn independently. Many of my pupils are much Gadgeteer and so are the teachers. They better GML programmers than I am and know not to come to me talk about it during the week. They are not expecting answers to their problems – they have other strategies which put off at the first hurdle when the code include posting questions and deconstructing existing games. Is that not doesn’t work, they are quite happy to fiddle the modus operandi of all commercial programmers? And what of the around and find their way through it.” club? Well it is still going strong but it is no longer small, nor is restricted Sue Sentance to the 11 – 13 age range. We now have a club for 7 and 8 year olds. Graham Hastings

SWITCHED ONONON web supplement: www.computingatschool.org.uk INTRODUCING ROBOTICSROBOTICS:: HAVING The submission deadline to the LOTS OF FUN WITH BITS AND BOTBOTSSSS annual UK schools animation competition is March 23rd. Lego Mindstorms NXT kit is proving a hit in a lunchtime club in Promising to be even bigger than Monmouth. Its easy interface has hooked the students, but, as previous years, pupils between Lyndsay Hope explains, the real benefit lies in provoking them the ages of 7 and 19 are to explore further into the capabilities of ’real’ languages. challenged to produce a one minute key frame animation. Last year we started working with We ran a Robot Challenge, over a Initiated by the University of robots in a Year 9 lunch time club. range of events including a Maze, Manchester five years ago, The students worked in small groups Sprint, Shot-Put and Target Shooting. Animation 12 has a huge following of three or four, equipped with the The students designed and built their in schools. Last year 563 schools NXT kit and a recipe for a basic 'rotate bots, testing them and reworking their registered, with 886 entries and shoot' sentry bot. It guided them designs as needed. Their particular received. Some 45 students from through the process of building their aptitudes came to the fore in the 25 schools won prizes last year. bot and creating basic programs using process, some focussing on design the built in software with its drag and elements, whilst others looked at The galleries on the Animation 12 drop interface - very useful for those refining the programming for website will provide inspiration. completely new to programming. The manoeuvrability, improved sensing Further details about how to students were shown how to upload a and more accurate shooting. Most of register are in the supplement. A program, operate and test its those Year 9 students have returned greater range of software is movement, introducing ideas like to the club in Year 10 with new ideas permissible this year, including sequencing, loops and iteration. and a keenness to explore still further. Scratch, Alice, Flash, DrawPlus, KoolMoves, SWiSH Max4 and Initially the computer was used to We have also embarked on an a Blender. Animations can be based control the robot using its built in multi-school science project for Sixth on any theme but this year there connection, however we Form students who have never will be a special category for discovered a free Android app called programmed but are keen to explore animations based around the life, MINDdroid, that did the job just as the possibilities. The learning curve is work, ideas and impact of Alan neatly from a mobile phone. This gave shallow and students are excited by Turing. Turing worked with the the freedom to walk the bots about, the swift results they get; they are University of Manchester following exploring different terrain and new keen on the creative aspects and on WW2, where computer pioneers challenges. It also introduced greater the opportunities they have to develop developed the first stored program ease of control, making handling more and experiment, to ask “What if?” and computer, ‘The Manchester Baby’ fluent, much like a game controller. get immediate feedback. in 1948. A separate competition, Codebreaker, using Greenfoot, Having built the initial bot from the Looking ahead, the next project has been organised in conjunction given instruction set, students were involves programming the robots with CAS. See overleaf for details. very keen to create different models. using Microsoft Robotics software (see supplement) moving away from the visual, drag and VPL CODE FOR ROBOTICS drop interface to Microsoft’s Visual Programming coding and giving Language (VPL) for robotics is other choices, for aimed at novices, based on a example using XBox “graphical dataflow-based model. controllers to control A dataflow program is more like a the bots. This is series of workers on an assembly proving interesting line, who do their assigned task as for senior students the materials arrive. As a result and also provides VPL is well suited to programming some of our juniors a variety of concurrent processing with useful examples scenarios.” See the web of practical coding in supplement for further details of a very engaging way. how to access this free resource. Lyndsay Hope

SWITCHED ONONON web supplement: www.computingatschool.org.uk WHERE DID MIND EXPANEXPANDINGDING TECHNOLOGY COME FROM? Technology develops at a bewildering speed. Today’s developers stand on the shoulders of giants. Roger To celebrate the centenary of Alan Davies praises a free book that looks at the origins of the Turing’s birthday in 2012, the Computing ideas that underpin the computing revolution. At School group has launched “Codebreaker”, a Greenfoot-based “You can’t understand where mind-amplifying technology is going programming competition for school unless you understand where it came from.” So says Howard students. A full range of prizes is available Rheingold in his introduction to ‘Tools For Thought’. Written in the early for each age group and the competition is 1980s, Rheingold was surveying the onset of the personal computer. free to enter. Many books tell that story as the work of Jobs, Wozniak, the homebrew clubs and teenagers in garages. Good as those stories are, Rheingold CAS are delighted that the Codebreaker points out, “If it wasn't for people like JCR Licklider, Doug Engelbart, competition is being offered as part of the Bob Taylor, Alan Kay, it wouldn't have happened. But their work was very successful Animation12 run by the rooted in older, equally eccentric, equally visionary, work, so I went University of Manchester and enables back to piece together how Boole and Babbage and Turing and von students to provide interactive Neumann created the foundations that the later toolbuilders stood upon programmed solutions on the theme. to create the future we live in today.”

In launching the competition CAS co- This is a wonderful book, freely available, though tucked away on his ordinator Simon Humphreys said “Alan website (link in the supplement). It explains the origins of the ideas on Turing was such an important figure in the which today's complex technologies rest, and it does so in an engaging history of computing; a national accessible fashion. Rheingold weaves a story that takes us from the competition aimed at encouraging students ideas of Babbage and Lovelace’s programming, Boolean logic and to design and implement a program on the Turing-type computation to the scientific and technological codebreaking theme is a fitting way to breakthroughs driven largely by the politics of the post war world. celebrate Turing’s life and work at Rheingold has a way of explaining complex concepts in layman’s terms Bletchley Park”. without robbing them of their depth. Thus he explains the importance of Information Theory, the early explorations in Artificial Intelligence, Using the Greenfoot IDE, students have to network technologies, developments in storage, processing and user create an interactive program which is interfaces. Most importantly, there is a chapter recognising the work of linked to theme of “Codebreaker”, either as Seymour Papert and Alan Kay. Their vision of the computer as a child’s a game or a puzzle. It is not intended that tool for thought, or, in Rheingoldian terminology, a mind amplifier is a the player task is to necessarily break a ‘must read’ for every computing teacher. It ends speculating about code - a general link to the theme is developments in immersive worlds and online communities many years sufficient. before internet use became a widespread.

The CAS website has a suite of resources Chapter three is a succinct explanation of Alan Turing’s major to support teachers including a 10-week contributions to this amazing history. His vision of a Universal Machine, after school club programme culminating in which could be programmed to perform as a ‘virtual’ machine is work devoted to the Codebreaker remarkable for its clarity as is the unification of his ideas on challenge plus supplementary resources programming, translation, debugging and machine dialogue. As the for researching the life and contribution of book makes clear, Alan Turing stands at the centre of the development Alan Turing and cryptography. For links of deep, rich, intellectual discipline - computing. see the web supplement. A CALL FOR TURING 110000 PARTICIPANTS Entries, which must be received by Friday 23 March 2012 can be submitted by Turing100 invite students, teachers and others to be a individuals or teams in four age categories, part of a historic and exciting event. Using the famous ranging from 7 – 19. These will be Turing test the preliminary phase will start soon and reviewed by a panel of judges and the continue till May. Participants will be asked to judge shortlisted winners will be announced in 'entities' on special Turing100 web pages. They will be May 2012. asked to judge the conversation ability (0=bad to 100=humanlike) of each of the six entities. See the supplement for details.

SWITCHED ONONON web supplement: www.computingatschool.org.uk APPRECIATING TURING’S WORK: TAKING PUPILS TO SEE STATION XXX If you have never taken pupils on an educational trip, the Turing centennial provides a obvious opportunity, and Bletchley Park an obvious location. This was the location of the wartime code breaking centre, where Turing played a central role.

The most famous of the codes and the surviving huts and learning more ciphers broken at Bletchley Park of this fascinating story. Other (known as Station X) were the Enigma buildings too, are steeped in history. The National Museum of machine generated ciphers, but lots of ‘Cottage Number 3’ was where the Computing houses the Colossus other coding systems used by Hitler first break was achieved, whilst ‘The computer rebuilt by Tony Sale and and his allies were also broken. Bungalow’, an old fruit store became a continues the history of the Behind the magnificent mansion in the think tank for early computer research development of computing from Buckinghamshire countryside, large by mathematicians including Turing, the 1940s to the present day. wooden huts were erected on the Gordon Welchman, Max Newman and lawns of the estate. These became Tommy Flowers. In 1943 the Nazis Operated separately home to the famous codebreakers of had developed Lorenz, a semi by the Codes and the Second World War and one of the automatic machine even more Ciphers Heritage birthplaces of modern computing and complex than Enigma. Newman was Trust, a visit is communications. convinced the answer to cracking typically made up of a Lorenz ciphers lay in developing a short introduction, A team including Turing made the first computing machine such as that tour or workshop and break in Enigma in early 1940. More described by Turing in his pre-war optional presentations. successes followed so that by April thesis. At the roundabout, some The NMoC is currently they had cracked both the German crumbling steps are all that remains of developing Army and Luftwaffe ciphers. The Block F. It was here, in late 1943 that presentations on process of breaking Enigma was due Tommy Flowers housed Colossus, • Computing history to a complex electro-mechanical Bletchley Park’s greatest success. So • The development of device, designed by Turing, known as successful was Colossus that a Mark storage The Bombe. The Enigma ciphers II model was designed and six were • The race to get faster were changed daily. The Bombes housed in Block H in 1944. Block H is • What exactly is a computer were operated by an army of Wrens in now the home to The National • The Turing machine Hut 11, greatly reducing the odds (and Museum of Computing (see right). time) to determine the ever changing The main exhibition centre is found in They also have a classroom with settings used. As the code breaking Block B whilst other buildings house a a rebuilt BBC computer cluster. work increased, the numbers working range of associated exhibitions. They currently offer workshops for at Station X swelled to over 9000 post 16 Computing students on personnel. Additional Bombe units Pre-booked school visits are • First Generation Machine Code were sited around Buckinghamshire, welcomed, tailored to different age Programming on PDP8s and by 1944 there were at least 200 in groups, with Computer Science • Second Generation Assembly use. themed visits organised through the Code Programming on PDP8s NMoC. Further details can be found • Third Generation BASIC You can take a group around the on their informative website. See Programming on BBC micros. grounds of Bletchley Park, identifying supplement for links. A group may combine these activities with a look at the FIND OUT MORE ABOUT BLETCHLEY PARK FROM CS4FN exhibition in Bletchley Park Our friends at CS4FN have lots of extra information about Bletchley showing the Enigma machines Park. Whether you want to know how you can help contribute to the and the work of the code restoration, the debate about just which machine can claim to be the breakers. Prices are dependent first computer, how the Bombe worked, or a host of activities on on the age of pupils, but very frequency analysis and code breaking their website has it all. Between reasonable. Further details on them, Bletchley Park, the NMoC and CS4FN websites will provide their website. students with an excellent resource for pre or post visit work.

SWITCHED ONONON web supplement: www.computingatschool.org.uk CREATING A GRAPH COMPILERS, GRAPHS ANANDD ALAN OF A CODE SEQUENCE As part of A-level Computing we TURING’S HALTING PROBLEM show the students a number of interesting techniques that they Teaching A-level Computing offers plenty of opportunities to could use in their projects, e.g. make links between different areas of the syllabus. John Stout unlimited precision arithmetic, shows how lexical analysis and graph structures can help graphs (of the Sales v students visualise the tricky concept of the ‘Halting Problem’. Temperature variety), validation, and sub-classing Windows It would be very useful if, before we ran a program, the IDE could warn about controls. potential problems with our program: not the expected type of syntax error, but the ‘Did you mean to do this?’ type of error. For example, Visual Studio warns us One useful technique is that of about using a variable before we’ve initialised it, not using a variable we’ve scanning: taking a stream of defined, and even paths through a function’s code which avoid returning a value. characters, and breaking it down into its tokens or components. When we program we’d all like to avoid infinite loops: wouldn’t it be great if the When a GetNextToken function is IDE could say ‘Hey, this program will never stop’ BEFORE we run it? This is the called a token class (identifier, core of the Halting Problem: Can we write a program that, when given ANY keyword, symbol, string, etc) is program and some data, tells us if it will halt or not when run with that data? returned, possibly with some additional information, e.g. the So where do graphs come in? Well, think about programs as a directed graph by name of the identifier, an 1. numbering each line of the program from 1 to n enumerated value for the 2. drawing a graph where each line in the program is represented by a vertex keyword, or the value of a 3. join two vertices i, j with an edge if line j of the program is (or could be) the line number. So, given some code like of code executed immediately after line i (i is the source, and j is the destination). this: If n <= 5 Then n += 25 The box above right shows the graphs that represent three sample programs. End If Notice that the graph feature that distinguishes a program that never halts (or repeated calls to GetNextToken possibly never halts) from one that always halts is the presence of a cycle give: (representing a programming loop); lines 2 to 3 / 3 to 2 in the second program keyword, If and 4 to 5,/ 5 to 4 in the third. If there is a way of avoiding (or getting out of a identifier, n cycle) then a program could halt – depending on the input. symbol, <= integer, 5 Generating the graph of a program uses a technique called scanning to identify keyword, Then endOfLine keywords such as If, Do, Loop, End and so on. The sidebar left explains the identifier, n concept in more detail. The algorithm to produce a graph can be written in symbol, += pseudo-code as integer, 25 endOfLine initialise keyword, End do until no more lines keyword, If endOfLine get next program line if this line is the destination of a previous line(s) then Scanners are really useful for generate one or more edges from their source to this line compilers, interpreters, and free- if this line is a source (backwards/forwards in the program) then form data entry. Rather than save this line’s number sprinkle lots of string handling code throughout our program we Once we have a description of the graph we can draw it using the DOT can just keep on calling the language. This is a very useful technique for some student projects. See the far GetNextToken subroutine and sidebar for more details of what is involved. The web supplement contains a decide what to do based on its simplified version of the scanning / graphing program written in VB. It only return value. The ‘deciding what to handles enough control structures to make its point, and has very little in the way do’ process is called parsing and of graceful recovery from errors. Nonetheless, it is a useful program to can be introduced to students demonstrate and worth studying. when looking at defining grammars using Backus Naur The heart of the program is in the function called graphURL which takes the text Form - yet another link between of a program (parameter programText) and returns a Google Charts URL to draw topics at A-level! the graph of that program. It creates an instance of the Scanner class on the program text, then scans through the text using, in essence, the algorithm

SWITCHED ONONON web supplement: www.computingatschool.org.uk 'ALWAYS HALTS USING DOT LANGUAGE Sub Main() 'SOMETIMES HALTS,DEPENDING ON DATA I = 1 Sub Main() I = I + 1 TO CONSTRUCT GRAPHGRAPHSSSS Dim N AS Integer = End Sub Console.ReadLine().ToInteger() Graphviz is free, open source If N > 1 THEN Do graph visualisation software. Loop End If You’ll find the link to their website 'NEVER HALTS End Sub in the supplement. Graphviz Sub Main() Do programs take a graph description Loop End Sub in simple text language called DOT. To draw the ‘Sometimes outlined previously. As always the devil is in the details, but the Halts’ graph, above left, using diagram right demonstrates the principle. For example, when finding a DOT we need to generate a text For loop (at line 5 say), it stacks a CodeNode object of type "For" and file containing: line number 5, then generates an edge from line 5 to line 6, and continues through the code inside the For / Next loop until it gets to a digraph SometimesHalts { Next (say at line 10), when it generates an edge back to line 5 and an 1 -> 2 -> 3 -> 6 -> edge from line 5 to line 11. Similarly, when finding an If / Else / End If 7; 3 -> 4 -> 5 -> 4; structure (at line 20) it stacks a CodeNode object of type "If" at line } number 20, generates an edge from line 20 to line 21, and continues through the code of the True branch. At the Else (line 25) an edge is The description is passed to the generated from line 20 to line 26, and then finally at the End If (line DOT language processor. An 30) edges are generated from line 25 to 31 and from 30 to 31. Stacks alternative is to generate a URL have to be used since programs can nest control structures of for Google Charts like this: different types within each other. chart.googleapis.com/ chart?cht=gv&chl=digraph Let’s get back to the halting problem. Students can find this difficult to come to {1->2->3->6->7;3->4->5- terms with. Turing proved that writing a program to determine whether any >4}&chs=150x150 program/data combination does or doesn’t halt is an impossible task. The argument goes like this: DOT has lots of other options for controlling layout, fonts etc but for 1. Imagine that we can write such a program, call it HaltChecker. If we give it our purposes this is all we need. ANY program (P), and the data that P is to be tested with (D), it ALWAYS returns True or False (True if program P does halt when run with data D, False when program P doesn’t halt when run with data D). This can be represented as the graph shown on the right. Notice that HaltChecker ALWAYS returns a value, i.e., it NEVER gets stuck in a cycle.

2. Now we write another program, let’s call it HaltCheckerPlus, containing the HaltChecker program as a subroutine, and using it in a sneaky way: HaltCheckerPlus doesn’t halt if HaltChecker says the program it’s testing does halt, and it halts if HaltChecker says the program it’s testing doesn’t halt. Again see the graph on the right to visualise this.

HaltChecker 3. Finally, let’s ask ourselves what happens if we run HaltCheckerPlus, with HaltCheckerPlus as the program it’s testing and as the data?

Answer: if HaltCheckerPlus would halt, HaltCheckerPlus doesn’t halt, and if HaltCheckerPlus wouldn’t halt, HaltCheckerPlus does halt!

4. We clearly have a paradox, yet each step of our argument is logical. The only thing that’s wrong is our first assumption: that we could write such a HaltChecker program in the first place. This is known as a proof by reductio ad absurdum.

The proof as outlined not only proves that we can’t write a HaltChecker program that works for EVERY program, but it also shows that there are programs (well, at least one) we can define but that we cannot write. The Halting Problem is a difficult idea to grasp but by showing the programs as graphs helps students to HaltCheckerPlus visualise the proof, whilst also drawing links between topics. John Stout

SWITCHED ONONON web supplement: www.computingatschool.org.uk

DR SEUSS, POETRY AND PROOF: THE TEACHING OF ARTIFICIAL SCOOPING THE LOOP SNOOPER If you, or your students are still struggling to INTELLIGENCE AS SCIENCE comprehend the undecideability of the Halting Problem, try this wonderful proof Aaron Sloman encourages teachers to get involved in written in the style of ‘Dr Seuss’ by resurrecting the teaching of AI in schools. Inspired by Geoffrey K Pullum of Edinburgh University. Turing's ideas on morphogenesis, he argues for extending the idea to a concept of meta-morphogenesis. No general procedure for bug checks succeeds. Now, I won’t just assert that, I’ll show where it leads: Some young learners decide not to take courses in programming I will prove that although you might work till you drop, you cannot tell if computation will stop. because they feel other scientific subjects have more academic value. One way of countering this is to emphasise the deep scientific content For imagine we have a procedure called P that for specified input permits you to see in the science of computation. As an alternative, which may be of whether specified source code, with all of its faults, interest to a different group of learners, a subgroup of members of CAS defines a routine that eventually halts. has begun to explore ways of introducing AI programming as a way of You feed in your program, with suitable data, doing science, e.g. modelling human reasoning, learning, planning, or and P gets to work, and a little while later use of language, by using languages specially designed to support (in finite compute time) correctly infers whether infinite looping behaviour occurs. such experiments in "thinky" programming. Many AI researchers are primarily interested in AI as the science of intelligent systems. If there will be no looping, then P prints out ‘Good.’ That means work on this input will halt, as it should. But if it detects an unstoppable loop, One of Alan Turing's highly influential papers, The Chemical Basis Of then P reports ‘Bad!’ --- which means you’re in the soup. Morphogenesis, put forward conjectures about how interactions among Well, the truth is that P cannot possibly be, molecules in a developing plant or animal could eventually give rise to because if you wrote it and gave it to me, I could use it to set up a logical bind large scale patterns, such as spots on a leopard, or the spiral patterns that would shatter your reason and scramble your mind. of fir cones. We can extend this idea. In many animals, not only new

Here’s the trick that I’ll use -- and it’s simple to do. physical structure, but also new information processing capabilities I’ll define a procedure, which I will call Q, emerge during development, including perception, motor control, use of that will use P’s predictions of halting success language, abilities to reason and plan and social competences. to stir up a terrible logical mess. Moreover the learning competences also change: what can be leant by For a specified program, say A, one supplies, human infants, 5, 10, 15 year olds and so on changes dramatically. the first step of this program called Q I devise is to find out from P what’s the right thing to say of the looping behaviour of A run on A. We can express this by saying that in addition to morphogenesis of If P’s answer is ‘Bad!’, Q will suddenly stop. information processing capabilities there is also morphogenesis of But otherwise, Q will go back to the top, morphogenesis (learning new ways to learn, for example). We can and start off again, looping endlessly back, till the universe dies and turns frozen and black. label this "meta-morphogenesis" (MM). In addition, what different species can learn, and what they can learn to learn, changes across And this program called Q wouldn’t stay on the shelf; I would ask it to forecast its run on itself. evolutionary time scales, another example of meta-morphogenesis When it reads its own source code, just what will it do? (actually meta-meta-morphogenesis - MMM). As far as I know, there What’s the looping behaviour of Q run on Q? has been very little explicit study of how to model varieties of MM, If P warns of infinite loops, Q will quit; although some beginnings are to be found in AI research on learning yet P is supposed to speak truly of it! and evolutionary computation. This appears to be a large new field for And if Q’s going to quit, then P should say ‘Good.’ Which makes Q start to loop! (P denied that it would.) expansion of the science of computation. In future we may have to learn to build useful systems that undergo meta-morphogenesis partly No matter how P might perform, Q will scoop it: Q uses P’s output to make P look stupid. under the influence of the environment in which they are applied. Whatever P says, it cannot predict Q: Perhaps we should start educating young learners to think about this. P is right when it’s wrong, and is false when it’s true! The AI group are collecting examples and links on this topic. Further I’ve created a paradox, neat as can be --- links in the supplement. Aaron Sloman and simply by using your putative P. When you posited P you stepped into a snare; Aaron Sloman has produced a podcast introducing rule-based Your assumption has led you right into my lair. programs based on an AI language, showing some of the power So where can this argument possibly go? of pattern-matching for structure-manipulation — crucial for I don’t have to tell you; I’m sure you must know. A reductio: There cannot possibly be systems that think, see, learn, solve problems, make plans, a procedure that acts like the mythical P. communicate, etc. The video includes interactions with a running You can never find general mechanical means program whose capabilities are extended during use, as it for predicting the acts of computing machines; acquires more information from a human. The program can be run it’s something that cannot be done. So we users must find our own bugs. Our computers are losers! remotely via a virtual machine provided by Lee Gillam. To run the code (and other tools) locally on a Linux system contact Aaron.

SWITCHED ONONON web supplement: www.computingatschool.org.uk WHEN SIZE DOES MATTEMATTERR (PART TWO): GETTING TO GRIPS WITH THE NOTION OF ALGORITHMIC COMPLEXITY The AQA Computing specification for A2 requires candidates to have some appreciation of the complexity of a problem defined as the growth rate of the algorithm which solves the problem, i.e. its big O complexity. Following on from the article in the last issue, Chair of Examiners, Kevin Bond suggests some practical ways to explain O(Log 2n) complexity to your classes . You don’t need a computer to simpler version can be constructed Number of Number of Number of demonstrate log2 n complexity. with just one baton. A strip of masking Sections Sections 2 Tests Consider a low voltage light at the tape with holes made at fixed intervals 128 27 7 bottom of a garden. The cabling is in covers the length of copper wire. 64 26 6 the ground. The light isn't getting Sections of the wire are tested as current, even though the power supply shown – the full length, then one half 32 25 5 in the shed is fine. The fault must be then one quarter and so on. Any 16 24 4 located without digging up too much circuit continuity tester can be used. If 3 of the garden. How? A technique you borrow a multi-meter from the 8 2 3 called the split-half method can science department ensure it can 4 22 2 quickly locate the fault. A hole (and measure resistance (unit Ω). 2 21 1 test) is made halfway between the shed and the light. If there is current Let's say that the break is between single break among 32 sections and between the shed and the hole, the 8cm and 16cm. With the probes of the six tests for 64 sections. The number break must be between the hole and current break detector in holes 0cm of tests increases by one when the the light. Applying the technique and 64cm the instrument should number of sections is doubled. This is again, you make a second test, half- indicate a high resistance to current shown in the table above. The number way between the hole and the light flow (indicating a break). Now move of tests is the same as the exponent and so on. In this way the number of the 64cm probe to the 32cm hole. The when the number of sections is holes is minimized and so also the meter should still indicate a high expressed as a power of 2, e.g. 16 time taken. resistance to current flow. Next place expressed as a power of 2 is 2 4. The the probes in 0cm and 16cm where a exponent in this example is 4. In This can be simulated in the high reading should once again be conclusion: classroom. Two batons slotted obtained. Finally, test the last section together on wooden dowels cover a 0cm and 8cm. This time the reading No of Tests = Log 2 No of Sections length of bare copper wire strapped to should be low, indicating an unbroken the lower baton with masking tape circuit between 0 and 8cm. Although Therefore, the growth rate of number and several elastic bands. The copper there are 8 sections in total, the split- of tests for this technique is O(log 2 n) wire is cut and separated slightly as half technique has reduced the where n is the number of sections. shown in the diagram so that the number of tests (needed to locate the This is shown in the line graph below small gap is invisible through the break) to 3. The same answer would where the number of tests grows by holes in the top baton. Nine holes are be obtained if the break was in any of one each time the number of sections spaced evenly with the two end holes the other sections, e.g. 16 - 32. Try is doubled. An explanation of the approximately 64 cm apart (at 0, 8, this for yourself. Pick a section at maths behind this can be found in the 16, 24, 32, 40, 48, 56 and 64cm). A random for the break and count the supplement. number of tests required. No of Sections How many tests would 256 be needed to find a 128 break between 0 and 64 4cm, with the wire split 32

into 16 sections? The 16

answer is 4 because 8

sections will need to be 4

tested 0-32, 0-16, 0-8 2 and finally 0-4.

Five tests would need to 0 1 2 3 4 5 6 7 8 9 be performed to find a No of Tests

SWITCHED ONONON web supplement: www.computingatschool.org.uk IBM PARTNERS WITH VITAL SUSSEX HUB EXPLORES APP TO PROVIDE IT INSIGHTS IBM's Smarter Planet initiative identifies DEVELOPMENT WITH YOUSRYOUSRCCCC the need for a smarter use of today's technology. Through the use of RFID tags At the Autumn meeting of Sussex CAS, Paul Clarke from and sensors, data can be harvested and Previca introduced an online development environment manipulated to provide the necessary he first developed in order to enable his daughter to output to allow us to make smarter explore and write code. decisions which will have a positive effect both in terms of profitability and YOUSRC (pronounced "You source") uses a very simple programming environmentally. IBM's Colleen Haffey language called ELC (named after the young YOUSRC coder Emma (Software IT Architect, IBM), Sophie Louise Clarke) that takes its roots from many of the common Bialaszewski (Community Programmes, programming languages around. Because of this it is a very good IBM) and Sue Nieland (Course Developer starting point. A language from which people can move on to more and Vital Specialist, E-Skills) facilitated an more complex and powerful environments. It is simple and the initial teachers’ workshop at Park House students can control their own learning and go at their own pace. By School & Sports College, Newbury. having an Android player they are able to go home and play their apps on their Android phones....no Blackberry or Apple as of yet. Presentations from Tony Horrocks (Smarter Planet), Alan Flack (Wimbledon technologies) and Chris Bray (Careers in IT) provided fantastic contexts for teaching students about smart systems design and development including the use of augmented technology, identifying usability of digital natives and ensuring that systems are instrumented, interconnected and intelligent. Following the pilots a series of further workshops have been provided at different venues. Lesson resources have been produced to help enrich computing at KS3. The series of connected lessons aim to get them to think differently about systems design and We have used it in our Year 8 classes and it has been a great development. They take students through success. Even though we didn't manage to get anything completed for the process of identifying problems they the competition there is always next year! Paul is always available for experience inside and outside of school, any request, even silly ones. It is a great way to the get the students using identifying new technologies, designing code and the whole development cycle. Following YouSrc we moved apps for intelligent use and presenting on to Alice and student understanding has increased dramatically in their solutions. Download details are in the comparison to the groups that hadn't done YouSrc before. They are web supplement. Pete Marshman different but it opens up access to many students who believe that they “can't do computers”. Thanks Paul. Genevieve Smith-Nunes

GOOGLE CS4HS GRANTS 2012 CAS hubs continue to grow, as teachers appreciate informal opportunities, like the Sussex meet above. Six new hubs held Google's grant program, Computer Science for their first meetings during November and December 2011: South High Schools (CS4HS) provides funding to Coast (Poole), Three Counties (Malvern), West Yorkshire (), universities who work with schools to engage NE Scotland (Elgin), West Midlands () and Hampshire students in computer science. In 2011, three UK (Alresford). Other CAS teacher hubs that met last half term were universities were awarded funding. Queen Mary Surrey, Norfolk, Bristol, Thames Valley and Bucks. They are University received continued support for their proving an invaluable source of support. There are still some CS4FN program, the University of Kent for areas not represented though. Please get in touch with me (see Greenfoot, and the University of Manchester for supplement for details) if you teach/live in the following areas and the UK School Computer Animation would like our help in setting up a hub: Cumbria, Northumberland, Competition. Applications for 2012 close mid Shropshire, Staffordshire, Lincolnshire, East Yorkshire, South February. Further details in the supplement. Yorks/Notts, Devon/Cornwall and Kent. Claire Davenport

SWITCHED ONONON web supplement: www.computingatschool.org.uk WOMEN IN COMPUTING: SCHOOL GETTING TO GRIPS WITH GCSE COMPUTINCOMPUTINGGGG PUPILS ENJOY INSPIRATIONAL DADAYYYY A course for ICT teachers wishing to extend their skills to teach When a group of Year 10 students from Bay House School, GCSE Computing will be offered Alverstoke in Hampshire attended a ‘Women In Computing’ at Anglia Ruskin University, event at the University of Oxford, Computer Science Chelmsford. The evening course Department they had no idea what to expect. will run for 10 weeks, from January 17 to March 27. The None of us knew what to expect from do could help us replicate thought theory to be covered will include: the day, but we were excited about processes and teach computers how • binary and hexadecimal the experience. The first activity was a to think. This is just one example of numbers lecture about what computer science how the two subjects cross over. • computer architecture is. We were given an insight into how • representing sound and a computer multiplies numbers, which After lunch we discovered more links with graphics was really interesting because what other subjects. For example a woman • networking seemed like a simple process to us talked to us about how computer • structure of the internet was actually quite complicated for the science and biology is used to make • algorithms and problem-solving computer. Computers don’t have the models of the human body and how same type of thought process that we these models are being used to test The programming language used have, so they have to be told every medicines without harming people. will be Python, using resources individual thing to do which makes already developed at last year’s doing the simplest of tasks complex. In the computer lab we used a summer school, as reported in the We also watched a presentation on program called GeomLab, which last issue. It will cover: ‘Flying Helicopters – Research into allowed us to create pictures on the • variables and assignment Unmanned Aerial Vehicles (UAVs)’. screen. The configuration of the • selection and iteration Computer science doesn’t always pictures allowed us to resize and • arrays and other data structures mean sitting in an office - it can save rotate the images. We were taught • file-handling lives too. The helicopters were how to assign functions which showed • working with an SQLite database programmed to find people after us how simple and fun programming natural disasters. can be and it inspired us to download The course has been offered in the program later to experiment more. response to the requests from ICT We heard about a new course in teachers to become familiar with Computer Science and Philosophy. I Finally we were taken around St John ’s the background required to deliver had never thought about these two College. We saw students studying in the new OCR GCSE Computing, together, but as the professor groups and got an insight into the which is proving very popular. Like explained, it made more sense in my work ethic, the friends, and fun that the Python Summer School, it is head. Philosophers answer questions come with studying at university. We hoped to make the resources about how we think and computer all learned a lot. It inspired us to look available online for teachers in scientists are trying to replicate the more into computer science and other areas to access. way we think in machines. Trying to consider it as one of our options for Sue Sentance understand why we think the way we later on in our lives. April Selby GOOGLE TRAILBLAZER PRIZES AT BIG BANG FAIR 2012 THINK COMPUTER SCIENCE As part of Google's ongoing initiatives to promote and encourage the Think Computer Science is an study of computer science, we will be attending the Big Bang Fair in annual event Microsoft Research Birmingham in March 2012. We hope to excite students with some hands hold to showcase the work of on experience and engage them through challenging analytical problems. computer science researchers Google will also award two prizes for the best computer science projects and to enthuse Year 8/9 students of 2012. As well as receiving £500 and a certificate, each of the two about the field of computer computing trailblazers (plus a guardian if necessary) will have the science. The 8th annual event opportunity to spend two days at one of the Google research sites in was held at the Imperial War Europe where they will be able to take part in tours, mentoring from Museum, Duxford on December Google Engineers, workshops and get involved in some hands-on work! 7th just as this issue was finalised. Further links to Trailblazer details in the supplement. Niall Byrne More details in the next issue.

SWITCHED ONONON web supplement: www.computingatschool.org.uk A YEAR OF RAPID PROGPROGRESSRESS KIDS’ COMPUTER WORKSHOPS FOR CAS MEMBERS IN CAS has made significant inroads in A HIT WITH TECHNOCAMPTECHNOCAMPSSSS raising the profile of Computing in Wales since the inception of the first CAS Hub in In mid October, 120 students from Swansea became the September 2010. We have focused on first pupils to experience a Technocamps Workshop. By the widening and developing our network of start of 2012, a thousand more school children will have Computing/ICT teachers, and have been attended Technocamps Workshops throughout Wales. active at national policy level by working with the Welsh Government and different examination boards.

Computing is certainly on the Welsh Government's radar from both education and economic renewal perspectives. It also underpins their wider "Delivering a Digital Wales" framework. Alongside the CAS contribution to national-level policy consultations, we have been working hard to raise the perception of Computing as an First through the door were pupils from academic discipline distinct from digital Morriston and Cefn Hengoed Schools. literacy. We have also focused on The interactive Workshops, delivered on campus at Swansea University, Computing as a core STEM subject, as helped the pupils get to grips with computer programming in a practical well as how it underpins science and and creative way. The pupils were from different year groups but research strategy. We have met with a enjoyed the same experience. Each Workshop began with hands-on number of Welsh MPs and AMs, as well as activities that encourage the pupils to think about the importance of policy advisors within the Department for clear, precise instructions, which is fundamental to programming. The Education and Skills, and will continue to first activity involves the participants dividing their tables into two teams spread the message! We have also had and secretly designing a mascot; they then have to give the opposite good coverage from BBC Wales. team instructions on how to recreate it without showing them the initial design. The second activity involves one pupil coming to the front of the Part of this success is down to CAS Wales' room and secretly drawing a picture; a second pupil looks at the image strategic collaboration with Technocamps , and gives instructions to the rest of the class on how to reproduce it. a £6 million project led by Swansea University that aims to inspire young The pupils were then introduced to programming: Scratch for the 11- to people aged 11-19 through a range of 13-year-olds and Alice for the 13- to 16-year-olds. Each pupil has exciting computing-based workshops on access to a MacBook Pro with which they are guided to create their own topics such as robotics, game individual animations and games. The Technocamps experience doesn't development, animation and digital stop there; follow-on material is provided on a weekly basis for use in the forensics. Funded by the European Social fun and stimulating atmosphere of an extracurricular Technoclub to Fund through the Welsh Government, it continue the pupils' development. Each group that attends a Workshop has the long term goal of encouraging will return some months later for a further day with an emphasis on young people to pursue careers in exploring the activities carried out in their Technoclubs. Computing and related STEM areas that will drive economic growth in Wales. We are currently developing further Workshops on diverse topics such Together with Technocamps, we jointly as cryptography, robotics, computer forensics, algorithmics, and general hosted the successful inaugural CAS problem solving through computational thinking. Topics are typically Wales Conference at Swansea University motivated by the research expertise at the partner Institutions in July 2011. (Aberystwyth, Bangor, Glamorgan and Swansea Universities). Furthermore, each Workshop includes an inspirational talk. In October There is much to be done; but by working these were given by Dr Philip Legg of Swansea University's Sports closely with Technocamps we feel we can Science Department who discussed app development and marketing, advance the Computing agenda in Wales, and demonstrated his MatchPad App which was at that time being used and be able to report on exciting by the Welsh Rugby team at the World Cup. Through these inspirational developments in these pages on a regular talks, pupils are given an insight into exciting projects taking place within basis. Tom Crick universities and industry across Wales, and are hopefully motivated to consider career opportunities in computing. Faron Moller

SWITCHED ONONON web supplement: www.computingatschool.org.uk SEVERAL ORGANISATIONS JOIN EXCITING YEAR AHEAD AS CAS GROUP GROWS FORCES AS CAS SCOTLAND IS BORN The numbers of people signing up for CAS grows weekly (see chart The Scottish Institute of Computing Educationalists (SIoCE) has below). Around 70% of the joined forces with other bodies to form CAS Scotland. Kate members are active school Farrell, chair of the new organisation, reports on the progress teachers; but there is a solid core of made during a very busy first term. IT professionals, software developers, parents, governors and CAS Scotland has have been working The Scottish Qualifications Authority is university academics. There is with and talking to the Royal Society currently developing new significant interest in encouraging of Edinburgh, BCS, The Chartered qualifications to replace current ones computing, as a subject, in our Institute for IT, Computing at School, at all levels as part of Curriculum for schools. The CAS message is Scottish Informatics and Computer Excellence. The SQA are publishing getting heard! CAS is a grassroots Science Alliance (Scottish Universities) draft documentation as it becomes organisation - it is you, the teachers, and various industry partners, as well available and have just finished who will make the difference. as participating in debates on the consulting on the unit specifications future of Glow and ICT in Scottish for the new National 4 and 5 This year will see significant Education. Oh, and doing some qualifications. These will be in our changes to the school curriculum. teaching when we have a chance! schools in 2013. The outcome of the National

Curriculum Review is not yet known The Royal Society of Edinburgh & As part of the Turing Centenary the but there are some indications. BCS, The Chartered Institute for IT Royal Society and University of There are likely to be changes to have seconded Jeremy Scott Edinburgh are running the T100 the accreditation of vocational (Principal Teacher of Computing at TwitTest Schools Project. Pupils have courses and their contribution to George Heriot’s School in Edinburgh) to decide which tweets are real and league table indicators. ICT, the to exemplify some of the Computing which have been created by an AI subject largely responsible for the and Information Science technologies software bot. This Turing Test for the huge uptake in vocational outcomes in Curriculum for next generation will allow pupils, qualifications has been criticised in Excellence. The focus for the project parents and teachers to explore just many quarters. The indication is that will be mainly Level 3 and Level 4 what intelligence is and how we really the government will favour a experiences and outcomes. As part of know if someone, or something, is slimmed down curriculum, with this work there is a new group on intelligent. Again, links can be found in flexibility for schools to decide what CompEdNet to gather the opinions the supplement. else to teach beyond. and suggestions of members for the project. Links to register can be found Finally, a brief mention of the first CAS There is a growing awareness that in the supplement. This project will Scotland hub meeting, hosted by Computing has been neglected in generate a range of materials and Claire Griffiths, on 15 Nov Moray, NE many schools (see the resources for CfE Computing courses Scotland. Eleven people attended to recommendations of the Livingstone appropriate for 1st to 3rd year pupils. hear guest speaker and local website Hope Report and the government's There will be three packs developed designer Sam Hampton-Smith - the response). ICT teachers could feel and released in 2012. first of many, we hope. Kate Farrell threatened by impending changes but an increasing number are recognising the opportunities CAS MEMBERSHIP 2008 --- 2011 available to develop computing. WHEN DID YOU JOIN? These exciting opportunities increase the intellectual standing of the department, inspire children and lay the foundation for future progression into KS4 computing courses. CAS is planning ways to support such teachers through the development of the on-line community, resource repository and training courses. Exciting times lie ahead! Simon Humphreys

SWITCHED ONONON web supplement: www.computingatschool.org.uk A PAUSE FOR THOUGHT FREE MAGAZINES FOR CAPTCHA - Completely Automated PublicTuring test to tell Computers and Humans Apart - is a challenge- PUPILS FROM CS4FN response test. They are used to prevent automated software from Most readers will be aware of the excellent posting to blogs, forums and wikis. free magazine for computing students but Computers are presumed unable to CS4FN have also extended their output to solve CAPTCHAs so users entering reach pupils drawn to computing through a correct answer are presumed other areas. human. It’s known as a reverse The team behind CS4FN has just released a new free Turing test, since a Turing test is magazine: Electronic Engineering For Fun. It casts their administered by a human targeting eye for a story on electronics and physical computing. a machine while CAPTCHA is The aim of the new magazine is to enthuse students administered by a machine about electronic engineering with articles about real targeting a human. leading-edge research on gadgets, networks, chip design, robots, satellites and technology. Inside the first A CAPTCHA may ask users to issue students will find stories about creating their own identify a distorted image. Some gadgets, Nikola Tesla, researchers making baby make them more accessible using robots, and computer chips embedded in tattoos. obvious questions ("The 2nd letter in "frogs" is?"). Image recognition Last term we also distributed Issue 3 of Audio. Audio CAPTCHAs use algorithms engineers want to create new sounds and even new involving extraction of colour or instruments to make them. They are responsible for writing other special point features, which systems that, for example, allow out-of-tune pop prima cannot be correctly extracted after donnas to actually sound great. Now sound has gone distortion, whilst still recognizable to electronic it opens up new ways for creating all sorts of humans. Imagination CAPTCHAs things—not just music. create images by applying a sequence of randomized distortions Many readers will receive SwitchedOn with their class on the original images. set of CS4FN—the original publication supported by a wonderful website. If not, you can order single copies Approaches available for cracking or class sets of any of our magazines for your CAPTCHAs include exploiting bugs students at no charge. For more information just visit in the implementation, improving the CS4FN website. Jonathan Black. character recognition software, or using humans to process tests. Spammers pay up to $1.20 per 1,000 solved CAPTCHAs to companies in some developing nations. Others attempt to beat visual CAPTCHAs by creating CAS...JOIN CAS...JOIN CAS...JOIN C programs that can do Pre- Computing at School was born out of our excitement with the discipline, combined with a serious processing - to remove background concern that students are being turned off computing by a combination of factors. Our goal is to put noise, Segmentation - to split the the fun back into computing at school. Will you help us? Simply mail: image into single character regions, and Classification - identifying membership @ computingatschool.org.uk characters in regions. Computers can relatively easily pre-process Many thanks to the following for help with this issue of SWITCHEDON : Clive Beale, Jonathan Black, Kevin Bond, Niall Byrne, Tom Crick, Claire Davenport, Roger Davies, Peter Donaldson, and classify, however humans Kate Farrell, Graham Hastings, Lyndsay Hope, Simon Humphreys, Peter Marshman, Faron Moller, remain better at segmentation. So, Simon Peyton-Jones, April Selby, Sue Sentance, Huma Shah, Aaron Sloman, Genevieve Smith-Nunes, John Stout, Andrew Tringham, Liz Upton . Front page image © The Bletchley Park Trust if you want to devise a program to beat CAPTCHAs, concentrate on SEE THE SWITCHED ONONON WEB SUPPLEMENT FOR MMOREORE LINKS ANDANDAND EXTRA INFORMATION segmentation. Lyndsay Hope www.computingatschool.org.uk Computing At School are supported and endorsed by: