Intro to Scratch

Being aimed at elementary students, Scratch itself is not difficult to begin using.  Mastering is a completely different thing.  Below is a video briefly explaining the basic elements of Scratch. If video isn’t your thing, you can scroll down where I’ve provided the same information with screen captures and written descriptions.

 

Blocks with different functions are the codes you work with.  These blocks are colour-coded in eight categories.  Blocks are stacked together to create scripts.  When activated, these scripts run and make the sprites (characters, backgrounds, anything) perform the actions in the scripts.

The Scratch interface shows the menu of blocks in the upper-left and the varieties of individual blocks in the selected category below them.  The window on the right shows your project and the space below shows the sprites and backgrounds.  The middle provides information about the selected sprite or background and the area where blocks can be dragged into and “snapped” together to create scripts.

Below is an overview of the different block categories.

Motion blocks made sprites move, change position, or change size made sense.  Positions are calculated by x and y coordinates on the screen that goes from -260 to +260 on both axis.

Looks blocks deal with costumes, colours, and layering of sprites.  These are used in changing backgrounds, the size of objects, or showing and hiding sprites when needed.

Sound blocks really had no surprises there.  You could import a variety of sound effects that came with the program, import mp3’s or record your own sounds/voice.

Pen blocks can leave trails of colour for whatever artistic purpose you have.  One use could be the project viewer’s mouse could leave a trail of a certain colour.

Control blocks that “contain” other blocks usually.  In for a script to play continuously it needs to have a “top.”  The picture below shows several caps that are needed to close up a script making it complete for continuous use.

Operator blocks some the more overtly mathematical elements.  I have only used the pick random and the “and,” “or,” and “not” blocks thus far from the operator blocks.  They are often the requirements or restrictions needed in order to activate/deactivate a script.

Sensing blocks enable scripts to know when different colours come in contact,  the mouse rolls over something, or when certain keys are pressed, and usually there is a reaction or response when one of these sensors are triggered. For example, if a character touches the walls of a maze, he is sent back to the start of the maze.

Variables blocks are created by you to monitor a specific detail of a sprite.  For instance, if a car drives off the road and into the grass beside it, the speed variable may need to be used to affect acceleration or handling.

You are able to import pre-made sprites and backgrounds within the program, import your own pictures or characters, or create your own as well as edit existing sprites and backgrounds in the paint editor.

One of the biggest problems I encountered was the correct ordering of scripts to achieve the desired outcome.  Often it turned into trial and error as I arranged and re-arranged longer scripts, unsure of and unable to diagnose the problem.  Seeing other projects with long, complicated scripts was incredible now that I know how difficult it can be to get all of the pieces in a puzzle to work properly.  Here is an example of a multilevel Super Mario Bros rip-off with multiple levels, characters, and obstacles all done using one script and one sprite.  The script just keeps going….and going.

Those are the basic blocks and pages you would deal with in beginning to use Scratch.  If you’re interested in learning how to begin connecting blocks and creating scripts, you can look at my resources page for links to tutorials for beginning Scratchers.