Companion site for the book. Novice teachers and those wishing to improve their practice will find in this book valuable conceptual insights that illuminate the subject, and research-informed pedagogy that really works. Organised around the English GCSE specification and packed with fascinating stories from the “hinterland” of Computing and priceless pedagogy tips, this is essential reading for the Computer Science teacher.

Online companion to the book published by John Catt Educational Ltd, now available!

Buy the book at or on Amazon here.

This website contains additional material referenced within the book, links to further reading and suggested additional activities.


Cover illustration

Alan conceived the cover art which features some of the characters and concepts explored in the book.

At top left we see Persian scholar al-Khwarizmi, whose name gave us the word algorithm, from where the line draws a famous photograph of Ada Lovelace, Victorian scientist and author of an algorithm for Babbage’s Analytical Engine.

Next the single line draws Tim Berners-Lee at CERN showing off the first ever website, before drawing Katie Bouman, astrophysicist and computer scientist on the Event Horizon Telescope project at MIT whose Python code created the world’s first image of a black hole.

Finally we see a woman relaxing in a self-driving car, representing cutting-edge computing applications of the 21st century. A single line draws the whole image, reducing the image to its essentials, representing abstraction, a key theme of computing which runs throughout the book.

Why read this book?

This book is for new or aspiring computer science teachers wishing to improve their subject knowledge and gain confidence in the classroom. And it’s for experienced computer science teachers who wish to hone their practice, in particular in the areas of explicit instruction, tackling misconceptions and exploring pedagogical content knowledge.

You will read some of the backstory to our subject – the “hinterland” – those fascinating journeys into history that make the subject come alive and place it in historical context. These stories will help you to enrich your lessons, cement core knowledge, develop cultural capital and help you excite a life-long love for the subject. We will go beyond the mark scheme to explore the subject knowledge behind the answers, giving you the confidence to discuss the field in greater depth, enabling you to use explicit instruction methods: presenting skills and concepts clearly and directly enabling student mastery.

We will explore misconceptions that arise when teaching our subject, so you can “head them off at the pass”. And we will look at teaching ideas – the pedagogical content knowledge (PCK) – exploring the helpful analogies, questions and activities that work for each topic: practices that can be lifted and dropped straight into the classroom to immediately enhance your teaching.

Trainee or pre-service teachers, NQTs and early-career teachers will find this book invaluable, experienced teachers will find it inspiring, and all will benefit from a fresh look at the hinterland and subject pedagogy that makes computer science a fascinating subject to teach.

About the author

Alan Harrison BSc. MBCS MCCT NPQML is Head of Computing at William Hulme’s Grammar School in Manchester. He is a Computing at School (CAS) Master Teacher and CAS Community leader, a content author for the Raspberry Pi Foundation and a National Centre for Computing Education (NCCE) accredited trainer. Holder of the NCCE Teach Secondary Computing certificate, Alan has written official content for Isaac Computer Science, the “Teach Computing” resources and Quizlet Inc.

Before training to teach in his mid-forties, Alan enjoyed a successful and varied career in IT, beginning as a graduate trainee operator of IBM mainframes, then a network administrator, an analyst/programmer and finally a certified cybersecurity consultant working with major banks and insurance companies.

Alan can be found in school holidays camping or staying in remote cottages with the family from where they can explore new trails but he always packs his eBook reader, due to his unceasing thirst for knowledge. Alan loves three things: computers, learning new things and pedagogy; this book allowed him to combine all three in a labour of love.

Chapter Abstracts and References

Click the “Menu” icon at the top of this site to browse through the chapter abstracts and follow the links to content referenced in the book.

Below are the references from the book Introduction and Acknowledgements

[1] Shulman, L. (1986). Those who understand: Knowledge growth in teaching. Educational Researcher, 15, 4–14.

[2] Mishra, P. & Koehler, M.J. (2006). Technological Pedagogical Content Knowledge: A Framework for Teacher Knowledge. Teachers College Record Volume 108, Number 6, June 2006, pp. 1017–1054, Columbia University.




















From the Conclusion chapter