Scratch materials
Modified:
I create Scratch materials in various contexts and will try to aggregate them here in the following broad categories:
- Scratch evangelism (or why you should use Scratch)
- Scratch assignments
- Scratch lessons
Scratch Evangelism
While Scratch was designed with young children in mind, I’m not the only one who believes it’s a great tool for teaching beginning computer science topics.
A presentation I gave to the Puget Sound Computer Science Teachers Association on the topic:
Scratch Assignments
Scratch lends itself very well to ad-hoc experimentation and open ended projects. When the goal in using it is to teach programming concepts, though, I feel structured assignments are necessary. If you want solutions or more information on any of these, please e-mail me at 
Tree (nested loops)
I expected this “tree drawing” assignment to be easy for students who had been in a Python class for seven months. Nested loops are difficult for students and I believe need to be emphasized separately from simple loops, but I hadn’t realized how much harder the concept is for students with weak math skills. These guys really struggled.
This experience really convinced me that teaching problem-solving strategies should be the focus of high school computer science classes. We talked a lot about pseudo-code and writing out some sample output to find patterns. I ended up giving them both the full analysis and the pseudo-code. For stronger students, sample output in a couple of different sizes should be enough.
HeleneMartin-Scratch-Tree-Assignment.doc
Graphing calculator (loops, spatial reasoning, lists)
A “graphing calculator” program worked well with high school students grades 10-12 with relatively weak algebra skills:
HeleneMartin-Scratch-Graphing-Assignment.doc
Screensaver (loops, patterns, random)
The next assignment I did with the same group of 10-12 graders with weak algebra skills involved drawing spirals starting from random locations. I also asked the students to create another sprite with behavior of their choice so they could investigate interaction between sprites. They found this assignment somewhat easier than the previous two.
HeleneMartin-Scratch-Spiral-Assignment.doc