My experiences teaching 'unplugged'

A common misconception is that computer science, or computing, is a school subject that requires a lot of time in front of a monitor and that programming should be the vast majority of what students get up to, but alternative curricula that focus more on teaching computational thinking without the use of technology exist, commonly referred to as Computer Science Unplugged, or merely ‘unplugged’ for short.

What is Unplugged?

CS Unplugged was a term coined in 1999 in a free downloadable ebook written by Tim Bell, Mike Fellows, and Ian Witten known as ‘Computer Science Unplugged: Off-line activities and games for all ages in which there are a wide variety of activities that demonstrate how computer science topics could be taught without the use of a computer, though at the time it did not assume that these would make it into a mainstream classroom curriculum and as such was not fully appropriated for use by teachers; more so for educational researchers. (Bell & Vahrenhold, 2018)

Today, it remains used as enrichment to computer science and IT (information technology) courses taught across key stages, though use of computers and digital technologies remains necessary to meet the requirements set by the English national curriculum. (HM Government, 2013) In my own school, it is a strategy I use with my Year 10 group to teach algorithms - alternating on a weekly basis to include sessions focusing on programming using Python.

My implementation within the classroom

My first inspirations for using this style of teaching came directly from the existing teacher of the class whom I was taking over from. While I am sentient of the fact that continuing to do something because it was always done that way is a danger that many teachers fall into, I knew that in this particular context it would be the correct course of action, and one that should minimise pupil resistance (or any other forms of teething) from having a new teacher leading the class, as class content and activities purposefully emulate what they are already accustomed to.

Becoming familiar with this style of teaching however was a complicated challenge, and involved not only ensuring that I could come up with tasks that not only impacted my students and facilitated necessary learning, but would also be moderately engaging and hopefully inspire some curiosity into the subject further. It was weird for me as a computer scientist to go back to basics, and relearn theoretical topics again to the point where I would feel comfortable teaching them without the aid of code and at the reduced scope necessary for a GCSE student, not for a postgraduate. For example, my first task when taking over my Year 10 group would involve introducing them to the new topic of algorithms and getting them acquainted with the bubble sort algorithm - an inefficient but straightforward means of sorting data. (Cormen et al, 2001)

Before breaking up for Easter, I taught a total of six classes to my Year 10 group, all of which utilised an unplugged teaching style:

  1. Introduction to Algorithms and Bubble Sort
  2. Insertion Sort
  3. Merge Sort
  4. Abstraction and Decomposition
  5. Searching Algorithms (Linear and Binary)
  6. Sorting Recap and Feedback

Assessment for Learning features in all of my lessons in order to evaluate my students’ learning and new acquisition, though following the conclusion of the sorting algorithm trilogy and moving onto other the module, a substantial homework task was set requiring the completion of one of each kind of sort. Students were given a week to complete the work and were also recommended to seek assistance in meanwhile if they required any further help with completing the task. They were additionally reminded of the importance and mandatory nature of completing the work as it would be reviewed in class following the deadline and a brief marking period. The sixth class was an opportunity to provide in-depth and personalised ‘deep’ feedback to individual students and a chance to sharpen up both common areas of difficulty, of which two minor issues were recognised, and to provide one-to-one support where applicable. This provision of deep feedback was a school-mandated requirement.

Potential advantages identified

The feedback provided to the absolute vast majority of the students were very positive and applauded the students' work and provided recommendations for slight improvements henceforth. At this time, I do not have any data or control groups to use in order to establish whether this is statistically a superior approach, though it is not mandated in the National Curriculum that students be able to implement these algorithms at the code / pseudocode level, but should be able to recognise them if presented with an example until they reach A Level. (Sargent & Hillyard, 2017)

Research undertaken by Rodriguez et al (2016) found that while CS unplugged activities do well to engage and teach students in isolation, however for longer classroom sessions they benefit from additional structure and content. Nevertheless, results were positive with all results in following examinations exceeding 50%, and many attaining results above 80%.

Potential disadvantages identified

Many students in my class expressed that they found the content boring and unengaging, and in the case of performing bubble sorts, tedious, due to being required to write out multiple series of values in a table. When questioned further about how they felt about the content and what they would prefer, all questioned why they were doing computing without using computers themselves and that they would rather be programming. This boredom was actually more prevalent in students requiring Stretch & Challenge, as they rocketed past some of their peers and were frustrated with the slower pace generally set for the remainder of the class. Furthermore, some parents commented that their children felt ‘a little bored’ or somewhat dissatisfied during a parents evening meeting that I was unfortunately not present for.

In order to help mitigate this, I both produced and appropriated stretch tasks, some more entertaining, and others more challenging in order to help prevent them from becoming distracting to other students or becoming unmotivated. Examples of these stretch challenges range from simple tasks such as word searches and crosswords to more complex tasks involving producing or annotating pseudocode. This came about as a recommendation from academic staff at Birmingham City University, who remarked after discussion that having a ‘treasure trove’ of resources for Stretch & Challenge students to use is a good idea. To my delight, I realised that this coincided with strategies already in place by the host teacher in programming sessions.

In a similar vein, Taub et al (2012) found that after exposing students in a United States middle school to unplugged activities that while they became more knowledgeable about what studying computer science might entail, but their desire to do so lessened. From my own personal experience as an educator, this is something that I have seen quite frequently not only in schools but also at universities, where students' expectations of studying computer science to be derivative of their enjoyment of technology, video games, and/or the Internet are not met and are taken aback by the scientific and mathematical content within the subject at large.

Final reflections

I have thoroughly enjoyed teaching my students using this methodology and believe that it is a fantastic addition to my teaching portfolio, and I believe that it is something that computing teachers and lecturers should look to incorporating within their own curricula either as the predominant or complementary feature of teaching many aspects. On the other hand, I do believe that it cannot exist alone as a sole source of computer science tuition and believe that a healthy inclusion of programming and screen time not only help mitigate some of the dissatisfaction and boredom that might arise from using unplugged activities but also help students apply theory into practice for the benefit of their learning destination. Many students who study computing at GCSE (or other Level 2 standards) will go on to study the subject at A-Level, at university, or embark on apprenticeships within the IT sector and enabling practical use of acquired skills helps lay the necessary constructivist foundations for further learning in these areas.

I will continue learning about unplugged curricula and how they can further benefit my teaching across all key stages, and hope to incorporate it further into my Key Stage 4 teaching, which has a higher ratio of programming-based activities and teaching supported by digital technologies.


  • Bell, T., & Vahrenhold, J. (2018). CS Unplugged—How Is It Used, and Does It Work? Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications Lecture Notes in Computer Science, 497–521. doi: 10.1007/978-3-319-98355-4_29
  • Cormen, T. H., Leiserson, C. E., Rivest, R. L., & Stein, C. (2001). Introduction to algorithms. Cambridge, MA: MIT Press.
  • HM Government. (2013, September 11). National curriculum in England: computing programmes of study. Retrieved April 28, 2020, from
  • Rodriguez, B., Rader, C., & Camp, T. (2016). Using Student Performance to Assess CS Unplugged Activities in a Classroom Environment. In Proceedings of the 2016 ACM Conference on Innovation and Technology in Computer Science Education (pp. 95–100). Arequipa, Peru: Association for Computing Machinery. doi: 2899415.2899465
  • Sargent, C., & Hillyard, D. (2017, June 22). OCR GCSE 2.1 Merge sort - YouTube. Retrieved April 28, 2020, from
  • Taub, R., Armoni, M., & Ben-Ari, M. (2012). CS Unplugged and Middle-School Students’ Views, Attitudes, and Intentions Regarding CS. ACM Transactions on Computing Education, 12(2), 1–29. doi: 10.1145/2160547.2160551
Oliver Earl
Oliver Earl
Software Engineer, CS Educator

Oliver Earl is a full-stack software engineer, game developer, and qualified teacher of computer science from the UK.