Greenfoot LIVE

In order to provide more ways to support teachers who are using Greenfoot (or thinking about using Greenfoot), as well as anyone else interested in Greenfoot, we are starting a series of live chat sessions:

Greenfoot Live
Programming Education Chat With The Greenfoot Team

Greenfoot Live will be a regular chat event where members of the Greenfoot team will be live online and talk about Greenfoot, among ourselves and with you – the users of Greenfoot. The event is aimed mostly at teachers who use Greenfoot in their classes, but also at general Greenfoot users.

We will discuss educational aspects, as well as general programming topics, related to Greenfoot.

You will have a chance to listen to us talk, as well as ask questions.

The first Greenfoot Live event will be held on

Monday, 8 May 2017, at 5pm UK time

That is

  • 5pm in the UK
  • 4pm GMT
  • 9am in San Francisco
  • 12noon in New York
  • 18:00 in Germany, Scandinavia, Italy, France, …
  • 2am in Sydney (sorry…)

You can join us here.

After this first event on 8 May, we will host Greenfoot Live every two weeks. Recordings of these events will be accessible afterwards for viewing retrospectively.

Don’t forget to mark this date in your diary with a big red pen and join us in a couple of weeks!

Scratch, Alice, Greenfoot—What’s the difference?

Do you remember the feeling when you were a kid and you had the fantastically rare chance to go into a sweet shop (or, as the Americans among us would probably say: candy store), and you actually had a bit of money, and you could buy something, and there was just so much choice? Wow.

(I still get a similar feeling now – not so much with candy, but with chocolates. Hmmm, chocolate…)

This is what it seems like with educational programming software. Some ten years ago there was not very much around (at least not much that was in widespread use and had good resources), and now there is plenty. For a teacher of introductory programming, it’s a bit like being the kid in the sweet shop: So much here to look at, so much good stuff. But so hard to choose!

If you haven’t used any of the current educational programming environments before, it’s hard to get your head around what’s in them. Just like the well known box-of-chocolates problem. When I talk about Greenfoot, I often get the question “How does it compare to Scratch?” or “How is it different from Alice?”

To help a little with that situation, we organised a panel session at the last SIGCSE conference called Comparing Alice, Greenfoot and Scratch which compared these three environments. “We”, in this context, were Sally Fincher and Ian Utting who organised the session, and Steve Cooper (Alice), John Maloney (Scratch) and myself (Greenfoot) presenting the environments. I really enjoyed the session – it was great to get one of the leading people involved in each of the development teams to present the environments, and it was well received: the room was packed full and the feedback was good.

But panels are transient – no good record is available for those who were not there. So we are now working on a series of articles for a special issue of the Transactions on Computing Education doing the same in writing. They should be published together in a single issue later this year, and include a paper on each of the three environments and a discussion section where we talk about commonalities and differences.

To read it, you have to wait until it comes out. But as a teaser, here is a graphic that we made for the papers, showing the target age groups for each of the three systems.

Target age groups for Alice, Scratch and Greenfoot

Maybe this answers one of your questions already. For everything else, you’ll have to wait a little longer.

Berlin – after one week

I have just reached the end of the first week of teaching here in Berlin, at the “Institut für Informatik“, part of the Freie Universität Berlin.

I am teaching a module called ProInformatik III: Objektorientierte Programmierung – a block course that runs every day with five hours of contact over four weeks.

So, what have I learned so far?

Apart from the fact that translating technical terms into German poses regular challenges (what’s the German word for Debugger?), that apparently my German sounds funny now (well, 18 years out of Germany have left their marks…) and that I can still use a blackboard with chalk (we had a power-out yesterday), one of the most interesting observations is that the students here are much more talkative, more engaged, and ask much more interesting questions than my students at home. Where does that come from?

Well, partly this comparison is unfair. This is a summer course that students can take as a taster before they start to study. If they pass it, and then enrol in the degree programme, they get full credit. This naturally leads to a selective audience. I would guess that it is much more likely that the well-motivated, organised, keen (and possible good) students participate in these voluntary summer courses, so I’m dealing with a subset that is probably easier to teach.

However, I wonder whether there is also another factor at work. In Germany – compared to UK – school starts a year later, and lasts a year longer (although that is just changing now, with most states in Germany changing from 13 years to 12 years of schooling). That means students enter university two years later.

Add to this the fact that Germany has compulsory military service (for males only) we get a situation – in this male dominated discipline – where many of our students are three years older than their UK counterparts.

In other words: Many start here at an age where UK students finish.

The effect is startling. Instead of dealing with kids, I’m dealing with young adults. I wonder whether another year of life before study wouldn’t be a good thing for UK students as well.

Royal Society report on the state of computing in UK schools

A few days ago, the Royal Society has announced a study on the state of computing education in UK schools, its problems and possible solutions. This has been quite widely reported in the press, for example here. The announcement itself makes for interesting reading. Its introduction starts:

Numbers of students studying computing are plummeting across the UK, with a fall of 33% in just three years in ICT GCSE students, a fall of 33% in six years in A level ICT and 57% in eight years in A level Computing students in England and similar declines found elsewhere in the UK.

It contains some good quotes from a range of people, such as this by Matthew Harrison, Director of Education at The Royal Academy of Engineering

“Young people have huge appetites for the computing devices they use outside of school. Yet ICT and Computer Science in school seem to turn these young people off. We need school curricula to engage them better if the next generation are to engineer technology and not just consume it.”

This is the latest development in a growing trend in the UK that recognises the dismal state of computer science education in UK schools, and starts to work on finding solutions. I became involved in this topic a couple of years ago, through the Computing At Schools (CAS) group, a fantastic movement of really motivated and smart individuals initiated by Simon Peyton-Jones. This has grown over the years with initiatives such as developing curriculum for schools, organising computing teacher conferences, and founding a computing teachers association.

While the announcement of the study contains little new to those who already had an interest in the topic, it’s great to see that the Royal Society is getting interested and getting involved. This helps getting more organisations on board with making a change (already apparent from the announcement) and will push the issue higher on the agenda of those who are in the position to make decisions.

There is no doubt at all in my mind that such change is urgently needed and important. Currently, there is a whole generation of kids, some of whom would make great and enthusiastic computer scientists, who never find out about the possibilities and joys of this exciting discipline.

Altogether a great development.

The Greenroom is open

Our Greenfoot project has been going well for a while. The software has been stable for a couple of years now, whenever we presented it we got excellent feedback, and user number have steadily grown (to about 20,000 downloads a month at the moment).

There was, however, one big gaping hole: easy availability of good teaching material. Educational software in itself actually has very little impact – no matter how good it is – if there is not also teaching material available that teachers can easily take and use.

The first step in addressing this was the writing of the Greenfoot textbook. This is done now and was published last year. But we wanted to go a step further. So now we have:

The Greenroom

The Greenroom is a community web site, where teachers can find and share teaching material, discuss ideas or problems, and communicate with each other and the Greenfoot development team.

We have adopted a wiki-style ownership model for teaching resources on that site: Instead of resources being owned by their original creator (as is the case in other resource repositories), here they are owned by “the community”.

Of course, proper credit is given to the creator (and all other contributors), but any resource is editable by anyone on the site. We hope that this may lead to collaborative development of resources. Maybe someone has a worksheet that they can upload, others can improve is, add exercises, translate it to other languages, or add ideas.

Resources may even be just an initial project idea, where another Greenroom member then might take up the idea and develop a small project, someone else might add exercises, and so on.

The idea of this style of collaborative development is quite ambitious, and it is not at all clear whether it will work. But one can always hope!

So far, the beginnings are looking promising: We opened the Greenroom less than three weeks ago, and so far there are already more than 200 teachers subscribed, and more than 20 different resources available. I am carefully optimistic.

In future, we plan to extend the Greenroom to add more local information, so that members can see groups and events in their local area that might be relevant to them.

Let’s see where it goes. For now, I just find it exciting to watch how people start to communicate in the Greenroom.

A Light In The Darkness

lightComputing education in schools is in a dire state—we have known that for some time now.

Over the last couple of years, reports came out thick and fast stating that school age students find computing boring, that fewer students are taking computing classes, that offerings of computer science in schools is declining, and that this is  leading to a severe skills shortage. All seemed to indicate that students are really not interested in programming anymore.

Then today I stumbled upon this report of a survey of UK GCSE school students. (For the non-Brits: the GCSE is a set of tests that students take at the age of about 16.) And the result: Many students want more programming!


Most students (63 per cent) said they would have liked more subjects to choose from. Topping the wish list for school based learning is computer programming voted for by almost a quarter (22 per cent).

So it’s not the students who are losing interest at all. It is just that computing in schools has gone so off track that it is actively turning the kids away. Lets go out and get programming back into schools!

Teaching My Daughter To Code, Part IV: Return of the Daleks

Welcome back, dear readers, to the fourth part of Sophie’s journey of writing a DrWho computer game with Greenfoot and Java.

If you have read the previous parts, then thank you for sticking with us for so long! (If not, you may like to start reading here: Part I, Part II, Part III).

I’ll try to make it short today – it’s been a long day, and it’s getting late. But this programming session I’d like to record took place five days ago, I have only sparse notes, and I’d like to get it down before I forget too much. I have been busy this week, so I haven’t had time to write this up earlier, but there was so much lovely and encouraging feedback on the previous posts that encouraged me to continue writing this up.

Thus, without further delay, on to the next task: Reaching the TARDIS with the energy pellets!
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Teaching My Daughter To Code, Part III: Prepare The TARDIS!

The third part of my endeavours to write a Dr Who computer game with my daughter

If you’re reading this, then you probably already have an idea what this is about: An ongoing project to write a Dr Who-themed computer game with my daughter Sophie, who is 10 years old. (Yes, she’s 10 now – it was her birthday earlier this week!)

This is the third part of this story. In part I we got the Doctor to move, and in part II we added some Daleks. This time, we giving the Doctor something to do, something worthy of the last of the Time Lords: Collecting energy pellets for the TARDIS.

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Teaching My Daughter To Code, Part II: Invasion of the Daleks

Second part of my endeavours to write a computer game with my daughter

A few days ago, I have written about starting to teach my daughter some programming by inventing and implementing a game with Greenfoot and Java. Here’s the second part of that journey.

This time, I had thought a little more in advance about what might be a good thing to tackle next. Putting floors in, so that the Doctor would just walk on those levels (and ladders to go up and down)? Or other moves: jumping, ducking, etc?

I decided the most interesting thing would be to put some opponents in – other actors that you could run away from, and who could catch you. With the Doctor, it’s pretty obvious who that should be: the Daleks! (They are the Doctor’s prime enemy, after all.)

When I came home from work, I suggested this to Sophie. Happily, she agreed.

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Teaching My Daughter To Code

First party of a journey of writing a Doctor Who video game in Java with my 9-year-old daughter.

Update: Part II, Part III and Part IV of this story are available now.

(Note: This post is more than 10 years old. Some of the Greenfoot code shown can be written more easily in newer versions of Greenfoot, using newer API methods.)

Yesterday, my daughter Sophie asked me to show her how to write a computer game. She is nine. (Well, only a few weeks away from being ten – at this age, a year still matters.) She has never written any code before. Now, there’s a challenge, if I ever saw one.

I am a computer scientist, and one of our projects is Greenfoot – a programming environment designed to teach kids (and older students) to code with Java. So far, that has all been part of my research work. Research into programming education, tool design, etc. I have used Greenfoot with kids (mostly about 15 years old), but more often I do presentations and workshops for teachers.

I have often wondered how low in age you could take Greenfoot. It’s Java, after all, not Logo. 15-year-olds clearly works. But 10 year olds? We don’t know.

So I told Sophie that we’d start making a game tomorrow. That was yesterday. So today was the day. Afterwards, I thought it might be interesting to try to record the process we’re going through — see what happens.

So here is my (hopefully continuing) diary of coding with my daughter… (Our results, live demo and source code, are at the bottom.)

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