evaluation

As a final task for this course I asked the students to evaluate the different programs and activities that we did. Here are some of the results:

Class votes of what students thought about what we did, out of 5 :
Scratch 4.3
Physics 4.1
Guest speakers 3.9
SVG icon / hacking sugar / command line 3.5
Turtle Art 3.5
Other activities 3.5
EToys 2.9

BEST THING
Physics (5)
Turtle Art (3)
new sugar activities (2)
SVG icon / hacking sugar / command line (2)
Sugar UI

WORST THING
Etoys (5)
Turtle Art (2)
blogging (2)
SVG icon / hacking sugar / command line
guest speakers
Scratch

MOST INTERESTING
Scratch (2)
Food force (2)
SVG icon / hacking sugar / command line (2)
Turtle Art (2)

guest speakers (2)
new sugar activities
etoys
Physics

MOST DIFFICULT
Etoys (9)
SVG icon / hacking sugar / command line (3)
Scratch
Turtle Art

Thanks again to the guest speakers: Rosemary about Timor Leste and Joel about the xo development

The SVG icon activity meant developing your own icon using raw XML and then hacking through the linux command line to replace the existing xo icon

Air Sok's final blog provides a positive account of what some students got out of this course

Thanks to the students for being a great class

scratchy etoys challenge: some results

I asked students to complete some challenges in both Scratch and Etoys and then provide screenshots and compare the programs. Nearly all students reported that they found Scratch easier to work with than Etoys. No big surprise in that. As Bert Freudenberg has pointed out:

The power of Scratch lies in its limited scope - several years of development and refinement went into it to find the smallest set of features that make it easily teachable while still broadly applicable
(follow the link for Bert's fuller comparison between the two programs)

Here are the challenges again (initially designed for Scratch) with a few brief comments and links to the students blogs for their screenshots and thoughts.

Challenge 1) Use the Letter shapes to write your first name on the page. Then introduce some special effects such as making the letters wobble and change their appearance.

One student did this in etoys as an extension. Since it was an extension he did not have to blog about it. He did a great job it etoys, with the letters of his name chasing themselves across the screen, but it lacked the whirl and fisheye effects that are easy to do in Scratch and are ideal for this challenge.

Challenge 2) Point, click and move
Make an object both point and glide towards the mouse position when you click on the stage
Hint: Motion > point towards
Hint: Sensing > mouse down?

I couldn't fully figure this out myself in etoys and so asked for help on the Squeakland list. I received a lot of help there and so was able to show the students how to do it in etoys. Their writeup is here

Challenge 3) Make Dan or Anjuli or Cassy or ballerina dance to a beat, using all of their dance shapes

Two groups did this. One of them made a series of drawings for the dancer. The other group just dragged the prebuilt images from Scratch into Etoys (both programs running in Windows) and that worked fine. I hadn't realised it was that easy to import images into etoys. The student work is here and here

Challenge 4a) Make two animals have a forwards and backwards conversation
Hint: Use broadcast
4b) Make it an interesting conversation with each animal speaking at least 3 times and making gestures too

I figured out how to do this in etoys but it wasn't very elegant. So, once again I asked on the list and received help from Yoshiki Ohshima who showed me a more elegant method using the Holder.

The student analysis of this task is here

Challenge 5) Make 2 different balls move around on the stage
a) the first ball moves in straight lines but bounces randomly whenever it hits the edge
b) the second moves randomly, changing direction all the time

Because this involved a random bounce off the walls of the Playfield in etoys I thought it was fairly easy. For a true bounce it would have been more difficult in etoys since it lacks a true bounce tile (which Scratch has) and so the students would have had to work out the formula.

oops - Bert Freudenberg has pointed out that the etoys true bounce tile is there and similar to the Scratch tile. I just found it in the motion pane. Thanks Bert. (update 29th November)

Student work is here

Challenge 6a) One sprite chases another sprite around the stage. The first sprite moves in straight line but bounces off the edge randomly. The chasing sprite chases the first sprite but is moving slower.
b) Extension – if the chasing sprite catches the other sprite then it says something sensible and makes a suitable sound

The students completed a comprehensive write up of this challenge here

Challenge 7a) Play all the different drum sounds automatically
Hint: create a variable for the drum number
b) Extension – keep recycling through all the drum sounds automatically

Etoys sounds not working so we didn't attempt this. I'm not sure why the sounds were not working for SoaS, I didn't get around to trouble shooting that.

Challenge 8) Make a sprite gradually grow in size and then shrink
Hint: make a size variable

My hint is not necessary here because it can be done without a variable in both programs. Eventually I figured that out and advised the students which simplified the task somewhat. Initially they did it in etoys using diffent sized pictures in a Holder but I told them I wanted a more flexible answer. Their work is here.

Challenge 9a) Count down on a timer. A rocket takes off when you reach zero
Hint: Use the number icons in the letters folder
9b) Your rocket has pulsating exhaust and disappears at the top of the screen

Not attempted partly because it is already an existing Project in the etoys gallery

Challenge 10) Add, multiply or subtract two variable numbers
Hint: Just to do addition only you will need 4 variables: firstNum, secondNum, answer (computer calculated) and myAnswer (human calculated)

This is written up in here (Scratch solution) and here (Etoys solution)

Challenge 11) Variable coloured squares
a) Write a script that can draw a square of any size
Hint: Make a variable for the side length
b) Use the variable square script to draw a series of square with variable sides, with a single click
c) Now add variable pen colour and pen shade to the variable square script and use it to draw a variety of different coloured squares, with a single click

NOT YET WRITTEN UP

One thing I noticed about part (c) is that it is difficult to programmatically increment colours in Etoys because they are not represented by single numbers

Footnote: I'll update the links to student work as it is completed in the next few days.

scratchy etoys challenge

I have asked my students to complete a challenge in Scratch, then build a similar challenge in etoys and then compare and analyse the work involved. For this task they are allowed to work in groups of two.

The challenges were initially developed for Scratch and so the hints below are applicable for Scratch. For day one of this task each group had to pick a different challenge. So far these challenges are being attempted (1-5, 6 and 8). This kept me busy today because there were a lot of questions about how to do different things in etoys. Most of them I could answer but I'm still trying to work out how to detect a mouse click for challenge 2 (we did work out how to point towards and follow the mouse though)

(correction: I have worked out how to point towards another object which is being moved by the mouse but can't see how to follow the mouse itself since the bearing tile does not accept world's mouse x and y as input)

1) Use the Letter shapes to write your first name on the page. Then introduce some special effects such as making the letters wobble and change their appearance.

2) Point, click and move
Make an object both point and glide towards the mouse position when you click on the stage
Hint: Motion > point towards
Hint: Sensing > mouse down?

3) Make Dan or Anjuli or Cassy or ballerina dance to a beat, using all of their dance shapes

4a) Make two animals have a forwards and backwards conversation
Hint: Use broadcast
4b) Make it an interesting conversation with each animal speaking at least 3 times and making gestures too

5) Make 2 different balls move around on the stage
a) the first ball moves in straight lines but bounces randomly whenever it hits the edge
b) the second moves randomly, changing direction all the time

6a) One sprite chases another sprite around the stage. The first sprite moves in straight line but bounces off the edge randomly. The chasing sprite chases the first sprite but is moving slower.
b) Extension – if the chasing sprite catches the other sprite then it says something sensible and makes a suitable sound

7a) Play all the different drum sounds automatically
Hint: create a variable for the drum number
b) Extension – keep recycling through all the drum sounds automatically

8) Make a sprite gradually grow in size and then shrink
Hint: make a size variable

9a) Count down on a timer. A rocket takes off when you reach zero
Hint: Use the number icons in the letters folder
9b) Your rocket has pulsating exhaust and disappears at the top of the screen

10) Add, multiply or subtract two variable numbers
Hint: Just to do addition only you will need 4 variables: firstNum, secondNum, answer (computer calculated) and myAnswer (human calculated)

11) Variable coloured squares
a) Write a script that can draw a square of any size
Hint: Make a variable for the side length
b) Use the variable square script to draw a series of square with variable sides, with a single click
c) Now add variable pen colour and pen shade to the variable square script and use it to draw a variety of different coloured squares, with a single click

Some activity reviews

The screenshots illustrate the playback feature of the Colours activity

I asked students to download new activities from Sugar Labs. By new I mean activities not present on the default distribution of Sugar on a Stick (SoaS). We spent some time playing and then I asked students to choose one and evaluate it under the following headings:

• description of the activity
• screenshot(s)
• rating, out of 5 stars max
• Positive, Negative and Interesting features
• Age suitability
• What would the user learn from the activity

The activities we have looked at so far with links to student evaluations are listed below:

• Colours: namelessurl
• Super Brain: AirSok, GIJoe
• Billiards: Smith
• Traffic: Control-Tech-Sama, Captain Awesome
• Food Force: Sugar28, Ann
• Maze: DarkDragonZz
• Tux Paint: KingJamesFan
• Typing Turtle: ticktock
• Bar Game: SoEasyMan
• Connect4: DisplayName07
• Tangram: sreesanth007

I'll add to this blog as more reviews are completed by the students (updated 22nd and 23rd November)

realistic constructionism

I came to understand that making Shape 31 with variables was a nice challenge in real maths and understanding of the application of variables, measurement, ratio, proportion and fractions



Students in schools are invariably brought up on textbook maths and so to apply real maths to a challenge like Shape 31 is daunting for most. Hence, the need arose for me to help them scaffold this challenge, to make it more accessible to them.

I would see this as realistic constructionism, avoiding the twin errors of:
a) Just throw them off the deep end and hope that they swim. A few will but most won't
b) Not setting a real challenge through fear that they will find it too hard, just stick to the safe exercises in the textbook

The way I scaffolded it was to first demonstrate an easier shape that nevertheless required the thoughtful and not just mechanical use of variables.

In looking at the Barry Newell (BN) shapes from this perspective it becomes clear that some shapes have sides that vary (eg. rectangle) while others have sides that are all the same (eg. regular polygons such as square, triangle, pentagon etc.).

So I decided to demonstrate how to do the rectangle because the variation in the sides (2 are longer, 2 are shorter) is relatively easy to follow. So, here is is:


I then set as challenges shape 3, shape 4, shape 6 and shape 31 (all shapes here). They had to be done as follows:

"Shapes with variable sizes using the box. The variation has to work for small and large sizes"

Nevertheless, I still found that students found this hard. The following problems arose:

• using subtraction instead of or as well as multiplication and/or division. ie. not understanding that proportions or ratios alter with subtraction and do not alter when using multiplication and/or division
• trial and error instead of using measurement and knowledge of fractions or proportion

I gave direct advice about these things. Sink and swim has it's place in highly controlled or 1:1 or self directed learning environments but in a larger class is mainly irresponsible teaching. But in retrospect I could have done better and in fairly obvious ways. For example, I should have supplied rulers and more encouragement / demand for students to measure shape lengths and achieve more accuracy in proportions.

Nevertheless, one thing I discovered was that to quickly check whether the variable shapes scaled correctly was to quickly type in a very large value (eg. 1000) into the box and then see if any gaps in the shape resulted.

I asked the students to write this up in a blog. The best write up so far has been from namelessurl, especially this remark, which provides an insight into how student's often operate in ways not intended by the teacher but that a well constructed task might alter that line of least resistance:

"There were two ways to work out what values were needed in order to create a shape which could change in size and still keep it's correct dimensions. First was to use trial and error and we had to simply guess each value until we got it correct. The other way was to use mathmetics and actually calculate the values. I mostly used trial and error because i was too lazy to do the maths but in the end i found that using maths i got a much more accurate shape."

turtle art: using heading to change colours

Some of the samples in turtle art such as colors.ta and candyvortex.ta are quite spectacular visually

I want my students to explain how they work, then make some modifications and explain how the modifications worked. Here are some questions I could ask them about candyvortex:

• How does colour work? What numbers represent which colours?
• How does shade work?
• How does heading work? Which numbers represent which directions?
• What do xcor and ycor represent? Describe the co-ordinate system.
• Why does the pen thickness vary in this example?
• What happens if you rotate right rather than left?
• What happens if you vary the forward and back values?
• What happens if you take out shade?

Then I realised this would be too much all at once for some students. So I thought up an introductory exercise rather than trying to do all of the above at once. My introduction just explains one thing clearly, how can the heading can be used to set the colour. Here are the screenshots

Update 14th September:
Tony Forster has pointed out how to display the colour number without the complication of storing variables in boxes. We can do this because the fill screen tile also erases any lines drawn on the screen, whether by the turtle or the show command. The screenshot below illustrates the better method:

Also Tony has demonstrated a clever method of displaying both the colour and the shade effects in the one script. To follow this one you need to know that colours vary between 0-90 in ROYGBIV fashion and that shades vary between 0-100 with 0 darkest, 100 lightest and 50 median. Once again see the screenshot below:

turtle tricks

Armed with my Barry Newell worksheet (40 shapes challenge) I introduced Turtle Art to my students today

Some interesting things from my perspective

Shape 13: the circle
The students used arc to do that one! Shock! That defeats the purpose of the original Seymour Papert logo idea of drawing a circle with only straight lines (such as forward something) are available. I had to laugh. Still, I can set that task as a separate challenge.

Shape 17: six triangle rotated around a point
One student did that using only forwards and turns. I showed him and a couple of others how it could be done using repeats, in fact a repeat inside another repeat. His solution was about 25 tiles, mine was less than 10. So the issue of elegance is one to point out here.

Shape 38: a bunch of squares rotated around the centre of a square
Every time I use this sheet I get some students saying that have done shape 38. Invariably they haven't. Instead they have done lots of repeats with sharp (reflex) angles and it ends up looking something like shape 38. What I eventually did was show them the secret of shapes 6, 7 and 38. Namely, to first draw a square using pen up and pen down so that the turtle finishes in the middle of the square. Once you have done this for one square the more complex shapes are not too hard

Here's an example showing how to do shape 7: