Scratch (Programming Language)

Scratch is translated into 70+ languages and is used in homes, schools, and after-school clubs in every country in the world. Scratch is often used in teaching coding, computer science, and computational thinking. Teachers also use it as a creative tool across many other subjects including math, science, history, geography, and art.

As of late 2017, there were more than 22 million registered members of the Scratch online community and more than 26 million shared projects, with roughly 25,000 new members and 30,000 new projects every day. The blocks-based grammar of Scratch has influenced many other programming environments and is now considered a standard for introductory coding experiences for children.

## Origin of Name

Scratching is a technique used by disc jockeys to mix music clips together in creative ways and produce different sound effects by manipulating vinyl records on a turntable. Scratch takes its name from this technique, as it lets users mix together different media (including graphics, sound and other programs) in creative ways.

## Philosophy

Scratch encourages the sharing, reuse and combination of code. Users are encouraged to create “Remixes” of another user’s project. Projects created and remixed with Scratch are licensed under the Creative Commons Attribution-Share Alike License. Scratch automatically gives credit to the participant who built on the original work and to the participant who created the original program.

It is part of a research to design new technologies to enhance learning in after-school centers and other

informal education settings, and broaden opportunities for youth from under-represented groups who can become designers and inventors. Scratch was iteratively developed based on ongoing interaction with youth and staff at Computer Clubhouses. The use of Scratch at Computer Clubhouses served as a model for other after-school centers demonstrating how informal learning settings can support the development of technological fluency, enabling young people to design and program projects that are meaningful to themselves and their communities.

## History

The MIT Media Lab's *Lifelong Kindergarten* group, led by Mitchel Resnick, in partnership with the Montreal-based consulting firm, the Playful Invention Company, co-founded by Brian Silverman and Paula Bonta, together developed the first desktop-only version of Scratch in 2003. Its purpose was to aid young people, mainly for ages 8 and up, to learn programming.

Scratch 2 was released on May 9, 2013. With its introduction, custom blocks can be defined within projects.

As of 2017, Scratch 2 is available online and as an application for Windows, macOS, Linux (Adobe Air Required), and unofficially for Androidas an apk file. The Scratch 2.0 Offline editor can be downloaded for Windows, Mac and Linux directly from Scratch's website. However, the unofficial mobile version must be downloaded from the Scratch forums.

Scratch 3 was released of January 3, 2019. It was written in HTML5 and primarily uses the WebGL, Web Workers and Web Audio Javascript APIs. It sparked a major controversy due to "Childish graphics" and Scratch 3 breaking thousands of projects.

## Educational Use

Scratch was made popular in the United Kingdom through Code Clubs. Scratch is used as the introductory language because creation of interesting programs is relatively easy, and skills learned can be applied to other basic programming languages such as Python and Java.

Scratch is not exclusively for creating games. With the provided visuals, programmers can create animated stories, informational texts, and more. There are already many programs which students can use to learn topics in math, history, and even photography. Scratch flexibility allows teachers to create conceptual and visual lessons and science lab assignments, as Scratch is a useful tool to create animations that help visualize difficult concepts such as plant cell mitosis, the water cycle, Galileo Thermometer or Hooke's Law Experiment. Within the social sciences, instructors can create quizzes, games, and tutorials that stimulate the mind and interact with the student. Using Scratch allows young people to understand the logic of programming and how to creatively build and collaborate. Scratch lets students create "meaningful personal as well as educational projects" which gives students a "practical tool" to express themselves after learning to use the language.

Harvard University lecturer Dr. David J. Malan prefers using Scratch over commonly used introductory programming languages, such as Java or C, in his introductory computer science course. However, there is a limited benefit in a college level education. Malan switches his course's language to C after the first week.

## Scratch 3 User Interface

From left to right, in the upper right area of the screen, there is a *stage area*, featuring the results (i.e.,

animations, turtle graphics, etc., full screen, and all sprites thumbnails listed in the bottom area. The stage uses x and y coordinates, with 0,0 being the stage center. The stage is 480 pixels wide, and 360 pixels tall, x:240 being the far right, x:-240 being the far left, y:180 being the top, and y:-180 being the bottom.

There are many ways to create personal sprites and backgrounds. First, users can draw their own sprite manually with "Costume Editor" provided by Scratch. Second, users can choose a Sprite from the Scratch library that contains default sprites, a picture using a camera, or clip art.

With a sprite selected in the bottom-right area of the screen, blocks of commands can be applied to it by dragging them from the Blocks Palette onto the center-left area of the screen, containing all the scripts associated with the selected sprite. Under the *Code* tab, all available blocks are listed and categorized as Motion, Looks, Sound, Events, Control, Sensing, Operators, Variables, and My Blocks. Each can also be individually tested under different conditions and parameters via left-click.