Finding your way around Scratch

This blog has been written with UK primary teachers in mind who, with recent changes to the National Curriculum, are facing the daunting task of teaching their children to program computers. Fortunately there are several programming environments which have been developed in recent years which are specifically designed to help children become programmers without the steep learning curve needed to comprehend the complexities of programming languages. Scratch is one of them.

Although Scratch is not the simplest to use, it probably has the most potential for helping children understand the basic principles of programming and also provides them with the knowledge to move on to more advanced programming techniques.

Scratch has been developed by MIT and as this is an educational organisation, it provides the application as a free download or the program can be used entirely online without the need for a download.

Download version

Once you have installed Scratch and started up the program you will be presented with the following screen.

Online version

Once you have registered with the Scratch Project. clicking on the 'Create' tab on their website will take you to this screen.

Key

• Palette buttons - change the types of blocks available for programming in the Blocks Palette
• Tabs -------------   switch the information displayed in the Script Area
• Script Area -----  where procedures controlling the Sprites or the Scratch environment are created and edited
• Blocks Palette -   where command blocks are displayed and selected for insertion into scripts
• Stage -------------   the window in which actions take place in response to Scripts 
• Sprites List -----   shows icons of the Sprites which have so far been created 
• Backpack -------   (online only) storage area for Scripts and Sprites which might be used later 

Glossary

• Background ----  the back cloth to the Stage Area
• Blocks ------------ commands, statements and instructions which can be slotted together to make a script
• Conditions ------ tested in If or Repeat until blocks. A condition checks to see, for example, if Sprites are touching, or when a variable equals or exceeds a certain value
  
• Costume --------  worn by a Sprite. Costumes can be changed to change the appearance of a Sprite
• Forever loop ---  the blocks inside the loop are carried out while the Script is running
• Green Flag button - starts all Scripts
• If loop block ----- blocks in the loop are carried out when conditions in the block header are met
• Looks blocks ----  blocks for changing the appearance of Sprites
• Operator blocks -  blocks for carrying out mathematical or string functions
• Random block -  an Operator block for generating random numbers between two limits
• Red button -------  stops all Scripts
• Repeat loop -----  blocks in the loop are carried out the number of times shown in the header
• Say block -------  attaches a speech balloon to a Sprite with a message created by the user
• Script -----------  a series of instructions used to control Sprites or the Scratch environment
• Sound blocks --- to play notes, drums or imported sounds or those recorded by the user 
• Sprite ------------ a graphic character which can be drawn or imported which responds to commands in a script
• Touching? -------  detects when a Sprite is in contact with another Sprite or a particular colour
• Variable ---------  a named object for storing numbers or characters