Week 4: Using Scratch to Develop Computational Thinking

After 3 years of specialized IT teaching, Scratch has become a familiar friend of mine. It is a perfect tool for students to develop computational thinking, through drawing on fundamental computer science concepts, designing systems and problem solving (Wing, 2006). While Scratch does not necessarily subscribe to a specific coding language, it does engage with several core concepts that transfer across most coding languages, such as sequencing, parallelism, loops, conditionals, variables, etc.

Scratch is a free online programming platform that enables students to create their own projects to share within an online community. It allows users to connect drag-and-drop block codes to create a code sequence, to ultimately create animations, stories, mono/multiplayer games, etc. Users can freely place, reorder and delete different block commands, encouraging students to develop computational thinking through trial-and-error efforts.

The creative capacity of Scratch is endless. Users can customize their projects with a wide array of pre-made sprites (characters) and backdrops (backgrounds), or alternatively import their own preferences. All projects start as a blank canvas. Users may also alternatively create “spinoffs” of other users’ creations. Furthermore, Scratch offers several free add-ons for students to express their creativity through multiple means. Below is an example of a project I created for a Stage 3 lesson on parallelism, whilst using the music add-on:

A class demonstration I did to encourage students to use parallelism and nested loops to create music. Featuring: Batman theme song, “Another One Bites The Dust” & “We will Rock You” by Queen.

However, students’ ability to creatively utilize Scratch is largely dependent on their ability to decompose their ideas, recognize and recognize patterns, and abstract necessary concepts in order to develop their code (Barr & Stevenson, 2011; Zhang & Nouri, 2019). It is therefore necessary to conduct a certain degree of direct teaching (which does not focus on creative output, but instead consolidates key concepts) in order to first build up students’ computational thinking. Many teachers find this difficult to implement due to the technicality of coding, and the lack of systematic lesson plans (Nienke van & Niejeuring, 2017). Several companies have attempted to resolve this gap, such as in-school programs such as ScopeIT Education, or afterschool coding classes.

However, it does not take a specialist teacher to implement this. Below are examples of how I have consolidated computational thinking skills in my 3 years of specialty teaching, which can be easily implemented by generalist teachers.

Firstly, simple concepts can be isolated and introduced through simple projects that focus on a single computational concept. For instance, in my stage 1 classes, I created a simple task to introduce conditionals, where students need to use if/then statements to animate a sprite as the backdrop changed colours. Though creative output is limited, students consolidate their knowledge of key concepts and further get to explore coding blocks.

Screenshot of a simple project to introduce Stage 1 students to the concept of conditionals. Students insert blocks in 7 conditionals as the background changes colour when the green flag is clicked.

When basic computational thinking concepts have been consolidated, more general projects can be introduced, training students to apply key concepts in different contexts. The following is a project I introduced to stage 2 students, to combine concepts of conditionals, variables, loops and parallelism. It is from such experiences that students develop their computational skills of decomposing, analyzing and abstracting, in order to use coding concepts creatively in their own projects (Zhang & Nouri, 2019).

Screenshot of the game of “Pong” I got my students to build (the one above was my example) – students use the green paddle to hit the ball to gain points within a certain time frame.

References:

Barr, V., & Stephenson, C. (2011). Bringing computational thinking to K-12: what is Involved and what is the role of the computer science education community? ACM Inroads, 2(1), 48-54.

Wing, J. (2006). Computational thinking and thinking about computing. Philosophical Transactions Of The Royal Society, 1(336), 3717-3725.

van Es, N., & Jeuring, J. (2017). Designing and comparing two Scratch-based teaching approaches for students aged 10-12 years. In Koli Calling ’17: Proceedings of the 17th Koli Calling International Conference on Computing Education Research (pp. 178-182). ACM Digital Library.

Zhang, L. & Nouri, J. (2019). Assessing K-9 Teachers’ Computational Thinking Skills through a Computational Thinking Test. Handbook of Research on Integrating Computer Science and Computational Thinking in K-12 Education. IGI Global. Doi: 10.4018/978-1-7998-1479-5