OCR A Level Computer Science Revision Resources (H046 / H446)
Scheme of learning
Typical A level lesson
Component 1 - Computer Systems
Component 2 - Algorithms and programming
Component 3 - Programming Project
Programming resources
More resources
Free resources
OCR AS and A Level Computer Science — What You Need to Know
These 162 revision videos cover every learning objective across the OCR AS and A Level Computer Science specifications — H046 for the AS qualification and H446 for the full A Level. Created by experienced Computer Science teachers with over 25 years of classroom experience, every video is carefully written to meet the precise requirements of the OCR specification rather than offering generic content. Whether a student is sitting the AS Level or continuing to the full A Level, they will find a dedicated video for each topic in their course.
Each video runs to around 12 minutes — detailed enough to cover the content at the right depth for A Level, while remaining focused and purposeful. Unlike GCSE, scaffolded note-taking prompts have been removed at A Level; students are expected to identify and record the key information themselves, developing the independent study skills that higher education and employers demand. We supply Cornell notebooks at cost price to support this approach.
Our videos contain all the content students need to achieve the highest grades in their OCR A Level Computer Science exams. We update them regularly as we learn from past papers, so the focus always reflects what matters most in the examination.
Covering Both H046 (AS Level) and H446 (A Level)
The OCR AS and A Level Computer Science specifications share a significant body of content, and our videos are clearly labelled to indicate which qualification each applies to. Students studying for the H046 AS Level will find everything they need within the relevant SLRs, while those progressing to the full H446 A Level are supported through all 26 units. Teachers can use these videos with confidence across both year groups, knowing the content is pitched appropriately and aligned with the current specification.
How to Use These Videos
For students — Watch each video and take Cornell notes, identifying the key information for yourself. At A Level, the scaffolding is removed intentionally; developing the habit of selecting and recording important material is itself an essential academic skill. Pair the videos with Smart Revise to embed knowledge through spaced repetition throughout the year, rather than leaving revision to the final weeks before your exams.
For teachers — These videos are designed for the flipped classroom. Setting a video as homework means students arrive at the next lesson having already encountered the content, freeing up classroom time for deeper discussion, problem-solving and addressing misconceptions. They are also excellent CPD for teachers looking to build their confidence across the full breadth of the OCR A Level Computer Science specification, which covers substantial and challenging content.
Pair with Smart Revise
Once students have worked through the videos, the next step is consolidating that knowledge through regular retrieval practice. Smart Revise — winner of the Teach Secondary Awards 2025 for Curriculum Improvement and trusted by over 200,000 students and teachers across the UK — supports OCR A Level Computer Science (H046 / H446). Teachers who have used it report significant improvements in results, with one describing how their A Level A* percentage increased after introducing Smart Revise to their students.
Complete Your Revision with the Resource Centre
Alongside the Student Stream videos, the Craig ‘n’ Dave Resource Centre provides a full suite of teaching and revision materials specifically for OCR A Level Computer Science (H046 / H446). These include schemes of learning and course calendars, lesson theory PowerPoints, structured learning records, micro-activities with answers, programming project guides, and interactive apps. Resources are written to the exact requirements of the specification and are used in over 1,000 schools across the UK.
Videos by Topic — OCR AS and A Level Computer Science (H046 / H446)
All 162 videos are organised by the 26 Specification Learning Requirements (SLRs). Select a topic below to access the videos for that unit.
Computer Systems
SLR 01 – Structure and function of the processor. Covers the ALU, control unit, registers and buses, the fetch-decode-execute cycle, CPU performance, pipelining, and the Von Neumann and Harvard architectures. Essential foundational content for both H046 and H446 students. View videos →
SLR 02 – Types of processors covers CISC and RISC processors, GPUs, multicore and parallel processing, and the factors that affect CPU performance. View videos →
SLR 03 – Input, output and storage. Covers input and output devices, primary and secondary storage, and the comparative advantages of different storage technologies. View videos →
SLR 04 – Operating systems and systems software. Covers the role of the operating system, memory management, scheduling, device management, virtual machines, and the features of systems software. View videos →
SLR 05 – Application generation covers types of application software, programming methods, and the roles of assemblers, compilers, and interpreters. View videos →
SLR 06 – Software development covers software development methodologies, including waterfall, agile, extreme programming, and the spiral model, as well as the role of testing throughout the development lifecycle. View videos →
SLR 07 – Types of programming language Covers the classification of programming languages, the characteristics of procedural, object-oriented and declarative languages, and the purpose of each paradigm. View videos →
SLR 08 – Introduction to programming Covers the fundamentals of programming, including data types, variables, constants, selection, iteration, subroutines and file handling — the building blocks of all programs at A Level. View videos →
SLR 09 – Compression, encryption and hashing. Covers lossy and lossless compression, run length encoding, Huffman coding, symmetric and asymmetric encryption, and hashing algorithms and their applications. View videos →
SLR 10 – Databases Covers relational databases, entity-relationship diagrams, normalisation (1NF, 2NF, 3NF), SQL, and the advantages of a database management system. View videos →
SLR 11 – Networks Covers network topologies, communication protocols, the TCP/IP model, IP addressing, the Internet and the World Wide Web, and network hardware. View videos →
SLR 12 – Web technologies cover HTML, CSS, JavaScript, server-side and client-side processing, search engine technologies, and the role of web technologies in modern computing. View videos →
Algorithms and Programming
SLR 13 – Data types covers primitive data types, binary representation of integers and real numbers, character encoding, and how data types are used in programs. View videos →
SLR 14 – Data structures cover arrays, records, lists, stacks, queues, trees, graphs and hash tables — their implementation and appropriate use cases. View videos →
SLR 15 – Boolean algebra Covers Boolean logic, logic gates, truth tables, simplification using Boolean algebra and De Morgan’s laws, and the application of logic circuits. View videos →
SLR 16 – Computer-related legislation covers the legal framework surrounding computing in the UK, including the Computer Misuse Act, the Data Protection Act, copyright and intellectual property legislation. View videos →
SLR 17 – Ethical, moral and cultural issues. Covers the wider social impact of computing, ethical frameworks, artificial intelligence, autonomous systems, and the responsibilities of those working in the computing industry. View videos →
Computational Thinking
SLR 18 – Thinking abstractly Covers the nature of abstraction, the difference between the problem-solving process and the representation of problems, and how abstraction is applied in computing. View videos →
SLR 19 – Thinking ahead: Covers preconditions, reusable program components, the definition of interfaces, and how thinking ahead underpins efficient program design. View videos →
SLR 20 – Thinking procedurally covers decomposition, the identification of procedures and the sequence in which tasks must be performed to solve a problem systematically. View videos →
SLR 21 – Thinking logically: Covers the identification of conditions, the use of Boolean operators, and how logical thinking underpins the writing of correct, efficient programs. View videos →
SLR 22 – Thinking concurrently Covers the concept of concurrency, when concurrency can and cannot be applied, and the practical implications of concurrent processing for program design. View videos →
SLR 23 – Programming techniques Covers object-oriented programming, recursion, event-driven programming, file handling and the practical application of these techniques in written programs. View videos →
SLR 24 – Computational methods covers problem recognition, divide-and-conquer, backtracking, data mining, heuristics, performance modelling, and pipelining as computational approaches to problem-solving. View videos →
SLR 25 – Algorithms Covers standard algorithms, including searching and sorting, their implementation in code, and the analysis of algorithmic complexity. View videos →
SLR 26 – Algorithms (continued) Continues the study of algorithms, including further analysis of time and space complexity, Big O notation, and the classification of problems as tractable or intractable. View videos →
About Craig ‘n’ Dave
Craig ‘n’ Dave was founded by Craig Sargent and Dave Hillyard — two Computer Science teachers with over 25 years of classroom experience, both holding degrees in Computer Science. Craig worked as a programmer for the Ministry of Defence before moving into teaching; Dave worked as an analyst programmer in the civil and military aviation sector before becoming a subject leader at the University of Gloucestershire for initial teacher training in Computer Science. Together, they bring decades of academic and industry expertise to everything they produce.
Their YouTube channel has attracted over 22 million views, their classroom resources are used in over 1,000 schools across the UK, and Smart Revise is trusted by over 200,000 students and teachers. The Student Stream videos were created specifically for the flipped classroom and are matched precisely to the OCR AS and A Level Computer Science specification — not adapted from generic content, but written from the ground up for each learning objective.
Frequently Asked Questions
What is covered in the OCR A Level Computer Science specification (H446)?
The OCR A Level Computer Science specification (H446) covers three broad areas across 26 Specification Learning Requirements (SLRs): Computer Systems, Algorithms and Programming, and Computational Thinking. Topics include processor architecture, operating systems, programming, compression, databases, networks, web technologies, data structures, Boolean algebra, ethics, and a range of computational thinking skills. Our 162 videos cover every SLR in the full specification.
Do the videos cover the OCR AS Level (H046) as well as the full A Level (H446)?
Yes. The OCR AS and A Level Computer Science specifications share a significant body of content, and our videos are clearly labelled by qualification. Students studying H046 AS Level Computer Science will find all the content they need, and teachers can use the same videos with both year groups where the specifications overlap. Combining both qualifications, our Student Stream provides comprehensive coverage for all OCR AS and A Level Computer Science students.
How do the A-Level videos differ from the GCSE videos?
At GCSE, our videos include scaffolded note-taking prompts that guide students in what to write down. At A Level, this scaffolding has been deliberately removed. Students are expected to identify and record key information independently, reflecting the higher demands of A Level study and building the academic habits needed for university. The content is also pitched at a significantly greater depth, covering topics such as computational complexity, Boolean algebra, compiler theory and concurrency that go well beyond the GCSE specification.
Are these videos sufficient to achieve top grades in OCR A Level Computer Science?
Yes. Our videos contain all the content students need to achieve the highest grades in their OCR A Level Computer Science exams. This is confirmed by student results and teacher feedback each year. One student reported achieving an A* in their A Level Computer Science exam having used the videos extensively during their revision. We also recommend combining the videos with Smart Revise to maximise the benefit of regular retrieval practice throughout the course.
Can I use these videos for flipped classroom teaching?
Absolutely. The Student Stream videos were designed with the flipped classroom approach in mind. Students watch a video and take Cornell notes as homework, then bring that knowledge into the classroom. For A Level, this is particularly valuable given the volume and complexity of the OCR specification content — getting students to engage with new material before each lesson means lesson time can be used for deeper exploration and application of concepts rather than first delivery.
How long are the videos?
ach video is approximately 12 minutes long — focused and purposeful, covering the essential content of each topic at the right pitch for A Level study. Students can pause and rewatch as many times as needed.
Change log
- 21/05/25 – SLR07 Types of programming language (A Level Only)
A-Level – Object-oriented languages Activity 5 rewritten and improved for Python.
Not uploaded yet. - 01/12/24 – Lesson theory PowerPoint 6. OCR A Level (H046-H446) SLR2 – 1.1 CISC vs RISC.pptx
Clarification update.
Not uploaded yet. - 01/12/24 – SLR 02 01. CISC, RISC Activity 4.pptx
Clarification update.
Not uploaded yet. - 29/11/24 – Essential algorithms and data structures (second edition)
Added handling an item not being in a linked list in pseudocode in the book and in the coded algorithms.
Not uploaded yet or to Kindle Publishing. - 25/03/24 – Those little extras pack: 05. A level Computer Science taster lesson for KS4 – run length encoding
Added Python examples of RLE algorithm. - 09/01/24 – Essential algorithms and data structures (second edition)
Updates to coded algorithms: linked list with an array - 25/09/23 – SLR 26 Algorithms (A level only)
Update to cheat sheets. - 21/04/23 – SLR 07 Types of programming language (A Level Only)
Added a Python version of 05. A-Level – Object-oriented languages Activity 3.pptx - 10/10/22 – SLR 02 01. CISC, RISC Activity 1.pptx + answer
“multiplying” should have been “adding”. Changes to the RISC instructions. - 05/10/22 – SLR 13 07. Real numbers using floating-point binary Activity 1 Answer.pptx + answer
Clarity added to second activity: number of bits for the mantissa and exponent. - 21/03/22 – SLR23 01-03 – Conversion utility program
Python version added. - 31/01/22- SLR 09 05. A-Level – Different uses of hashing Activity 1.pptx + answer
Strengthened activity to include features of good hashing functions. - 18/01/22 – SLR 05 03. Open-source vs closed-source Activity 1 Minor correct to remove a mistake in the definition of open-source software.
- 13/01/22 – SLR 04 04. Scheduling Activity 3
A roll and write game to play with students illustrating the first come first serve scheduling algorithm. - 13/01/22 – SLR 07
Assembly language activities copied from SLR8 to avoid confusion. - 13/01/22 – SLR 08
Revised LMC activities. - 13/01/22 – SLR 19
New and revised activities. - 13/01/22 – SLR 18
New activities. - 13/01/22 – SLR 23 06. A-Level – Recursion Activity 2
New activity answer and sample program. - 13/01/22 – SLR 24
New activity and renumbering of existing activities. - 04/01/2022 – SLR 11 04. A-Level – Network security Activity 2.pptx
Improved some definitions and added some more difficult examples. - 04/01/2022 – SLR 17 01. Ethical, moral and cultural issues Activity 1.pptx, 01. Ethical, moral and cultural issues Activity 1 Answer.pptx
Update to the URL for the main activity and minor improvements. - 03/01/22 – Essential algorithms and data structures (second edition)
Most of the book has been rewritten. - 02/12/2021 – Minor update to 1 OCR A-Level Linear – 1-week model (scheme of learning).pdf to add details of Merge sort and Quicksort videos on page 37.
- 25/11/21 – Theory PowerPoint OCR A Level (H446) The A-star pathfinding algorithm revisited.pptx
Updated worked example. - 16/11/21 – SLR 26 Files named 10. A-Level xxx
Files with this prefix had lost their answer files. All activities have been updated with new answer files included. - 04/11/21 – SLR 13 06. Converting binary, hex and denary Activity 3 Answer.pptx
MSB was missing from the answer. Now added. - 14/10/21 – SLR1 02. Fetch-decode-execute image.pptx, SLR2 01. CISC, RISC processor comparison.pptx
Updated to compare RISC & CISC architectures more easily. - 30/8/21 – Schemes of learning
All calendars and schemes of learning updated. - 02/07/21 – Remastered videos
All 162 videos have been updated with PowerPoint presentations provided. - 01/07/21 – Revised SLR 14 Data structures
Assessment sheets updated. All activities updated with new ones added. Code examples now in Python, VB and C#. - 09/06/21 – Revised SLR 16 Computer-related legislation
Updated most of the activities. - 12/05/21 – SLR 14 02. Stacks and queues Activity 2 Answer.pptx
Corrected order of numbers 2 and 6 on the stack. - 27/03/21 – Revised SLR 02 Types of processor
Changed CISC/RISC activities to better reflect the evolving facts with these architectures.
Minor updates to assessment sheets. Updated Smart Revise questions. - 09/03/21 – Revised SLR 10 Databases
Added some suggested additional clarity to the normalisation activities to match mark schemes. - 08/02/21 – SLR 03 A Level teacher marking checklist.docx and SLR3 AS Level teacher marking checklist.docx
Did not include virtual storage in the depth section of the marking checklist. Now added. - 04/02/21 – Revised SLR 10 Databases
All the resources in this SLR have been reviewed and improved including to make them more suitable for home learning. More normalisation exercises with worked examples. SQL activities with DB Browser and SQLite 3 (free to use). Examples of using SQL with Python and C#. - 17/11/20 – SLR 19 (AS & A) – Thinking ahead (A4 scaffolded).pptx
Mismatch with A3 version. Fixed. - 31/8/20 – All SLR cover/assessment sheets