Scratch is a block based programming language. With that being said it is very powerful and there is no way I’ll be able to cover everything about it in the next few days – I’m just hoping to whet your appetite and you’ll seek out more, or just have some basics to introduce it to your students with some confidence. Today we’ll jump into getting things to happen, or “events”.
July 7th – A Week With Scratch
From Wikipedia: “is a programming paradigm in which the flow of the program is determined by events such as user actions (mouse clicks, key presses), sensor outputs, or messages from other programs/threads.” There are a number of Programming Paradigms out there, but I would say that students are probably able to grasp the event driven idea the easiest in terms of the reason things generally happen.
Once you’ve logged into (or opened the downloaded version of Scratch) you’ll notice the 8/10 colored blocks with labels – Motion/Looks/Sound/Pen/Data/Events/Control/Sensing/Operators/More Blocks.
Scratch 1.4 doesn’t include the “Events” as it is included in the “Control” section and Data is called “Variables” and “More Blocks” doesn’t exist – making 8 sections.
Today we’re focused on the “Events” in Scratch 2.0.
The first thing you’ll notice is the color – brown. This should be at the top of every script you (or your students write). The three we’ll focus on here is the “When Flag is Clicked”, “When ____ Key Pressed” and “When this Sprite is Clicked”. These three will give you and students a pretty substantial skill set to create anything you could think of.
One activity I do with my students right away relies heavily on Inquiry and the simple “hands on” nature of Scratch. I instruct my students to look at the “Event” blocks and drag and drop the “When ____ Key Pressed” event block and clicking on the drop down menu to see you can select keyboard keys. I have them select the Up/Down/Left/Right (or A/S/D/W) and figure out who to get the cat (default sprite) to move. They look in movement and find the “move __ steps” block – but what about directions?
The dirty little secret? There are at least 3 ways to do this, and none are *wrong*. A few are more efficient – which is a conversation for your students later.
Once the students start dragging and dropping the Motion Blocks and finding out they can’t really break the machine – a huge change happens – they enjoy themselves. They start trying things and programming keys, programming the Sprite and other things to happen once the flag (or I equate it to a start button) is pressed. Tomorrow I’ll talk about have having a program create its own events, because you’ll quickly find out that students have some great ideas – and you can support them!