Term 1
Unit 3: Data Representation
This unit explores exactly how a computer stores different types of data at the machine level. This covers advanced binary mathematics, digital image/sound structuring, and error-checking mechanisms.
Knowledge:
- Number categories (Natural, Integer, Rational, Irrational, Real, Ordinal).
- The difference between unsigned/signed binary and Two’s Complement.
- The architecture of floating-point numbers (mantissa, exponent, normalisation, underflow/overflow).
- Digital sound principles (sample rate, resolution, Nyquist theorem, MIDI).
- Information theory principles including Run Length Encoding (RLE) and dictionary compression.
Skills:
- Converting between decimal, binary, and hexadecimal bases.
- Performing binary addition/multiplication and calculating absolute/relative rounding errors.
- Calculating exact storage requirements for bitmapped images and audio files.
- Encrypting/decrypting using Caesar and Vernam ciphers.
How you can help at home:
- Inspect Family Files: Look at a digital photo on a computer. Go to ‘Properties’ or ‘Get Info’, and ask your child to calculate why that specific photo is 4MB based on its resolution and colour depth. Convert an audio file to an MP3 and discuss what data was “lost” during compression.
- Cipher Decoding: Write a short, encouraging note to your child but encrypt it using a simple Caesar Cipher (shifting every letter by 3 spaces in the alphabet). Leave it on their desk and ask them to apply their cryptography knowledge to decrypt it.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of machine-level data representation and information theory. Past paper questions will be a mix of ‘shade the lozenge’, mathematical calculations, and longer written explanation questions.
Unit 2: Problem Solving and Theory of Computation
This unit focuses on computational thinking. Students learn how to dismantle complex, real-world problems and model them logically before writing any code, heavily utilising Finite State Machines and abstraction.
Knowledge:
- Exact definitions and applications of abstraction (representational, procedural, functional, and data).
- The principles of decomposition, composition, and automation in problem-solving.
- The theoretical mechanics of Finite State Machines (FSMs) with and without output (Mealy machines).
Skills:
- Designing algorithms using pseudocode and hierarchy charts.
- Translating state transition diagrams and tables into working logic.
- Hand-tracing complex algorithms to deduce outputs and uncover logical errors.
- Articulating how a program works, arguing for its correctness and efficiency.
How you can help at home:
- Map the Real World: Next time you use a self-checkout machine or a washing machine, ask your child to quickly map out the “states” on a piece of paper (e.g., State 1: Filling with water -> State 2: Spinning -> State 3: Draining). This makes theoretical Finite State Machines highly practical.
- Abstraction Practice: Ask them to give you directions to the local shop. If they include irrelevant details (like the colour of a house on the corner), tell them to apply “Representational Abstraction” and give you only the data necessary to solve the problem (turn left, walk 100m, turn right).
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of problem-solving methodologies and computational models. Past paper questions will be a mix of ‘shade the lozenge’, short answer, and longer algorithmic or logic-based questions.
Unit 1A: C# Basics
This unit establishes the foundational programming structures essential for A Level. Your child will transition from GCSE level programming to advanced implementation in C#, mastering control structures, arithmetic logic, and modular programming.
Knowledge:
- The theoretical principles of sequence, selection, and definite/indefinite iteration.
- Built-in data types (integer, real/float, Boolean, character, string, pointers/references, records, arrays).
- The distinction between variables, constants, and the scope of local vs. global variables.
- How subroutines (procedures and functions) manage execution flow and memory.
Skills:
- Implementing arithmetic (exponentiation, modulo, truncation) and relational operators.
- Using Boolean logic (NOT, AND, OR, XOR) to formulate complex conditional statements.
- Executing string-handling operations (concatenation, substring, character code conversions).
- Constructing subroutines with parameter passing and value returns.
How you can help at home:
- The “Rubber Duck” Method: When your child is stuck on a programming error, ask them to read their code aloud to you line-by-line, explaining what each line is supposed to do. Explaining technical logic to a non-expert forces them to slow down, and they will almost always spot their own logic error mid-sentence.
- Variable vs. Constant Hunt: Ask them to look at a recipe or a board game’s rules. Have them identify what elements are “Constants” (things that never change, like the number of 2 dice) and what are “Variables” (things that change, like Player 1’s score or the dice values after each roll).
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of fundamental programming constructs and data types. Past paper questions will be a mix of ‘shade the lozenge’, short answer, trace tables, and longer programming-based questions. Additionally, your child will have two summative assessment assessing all content taught to date. Past paper questions will be a mix of ‘shade the lozenge’, short answer and longer answer coding/written questions. This should be read in conjunction with the AQA subject content within the specification.
Unit 13A: Analysis (NEA)
The NEA is an extended project where students act as professional software engineers to develop a programmed solution to a real-world problem or investigation of their choice. It is worth 20% of their final A Level grade (75 marks total) and provides an opportunity to independently showcase their advanced programming skills and deepen their understanding of computer science.
This unit focuses on identifying, researching, and precisely defining a complex computational problem to solve.
Knowledge:
- Problem identification and research methodologies.
- Definition of target users and measurable objectives.
- Entity-Relationship data modelling principles.
Skills:
- Producing a clear problem statement.
- Outlining specific, measurable, and unambiguous objectives.
- Creating data models to inform the design stage.
How you can help at home:
- Act as the “Target User”: Allow your child to formally interview you about what you would want a piece of software to do. Help them narrow down vague ideas.
AQA Specification:
Links:
Assessments:
Your child’s written report will be internally assessed and externally moderated against the AQA Level of Response mark scheme for ‘Analysis’, worth a maximum of 9 marks. Top marks require a fully scoped analysis with no relevant omissions.
Unit 6: Communication: Technology and Consequences
This unit zooms out to evaluate the ethical, legal, and environmental impacts of computer science. Students also learn the foundational concepts of network topologies and communication protocols.
Knowledge:
- Individual (moral), social (ethical), legal, and cultural issues (e.g., AI bias, data privacy, e-waste).
- Fundamental communication methods: serial vs. parallel, synchronous vs. asynchronous, simplex/half-duplex/full-duplex.
- Network topologies (Star, Bus, Mesh) and their respective efficiencies.
- Standards and protocols governing wireless networking (Wi-Fi, Bluetooth).
Skills:
- Evaluating case studies regarding the legal consequences of computer misuse.
- Comparing bit rates, baud rates, bandwidth, and latency of different communication channels.
- Debating the societal trade-offs of emerging technologies and digital surveillance.
How you can help at home:
- Host a Dinner Table Debate: Bring up a current tech news story (e.g., schools banning AI like ChatGPT, or a corporate data breach). Ask them to argue for the technology, and then against it. This builds the critical evaluation skills needed for essay questions.
- Home Network Audit: Ask your child to map out your home network topology. Have them identify the router, the wireless access points, and debate whether your home uses a “Star” or “Mesh” topology.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of communication technologies and the societal consequences of computing. Past paper questions will be a mix of ‘shade the lozenge’, short answer, and longer essay-style written questions.
Term 2
Unit 1B: C# Advanced
Building on Unit 1A, this unit introduces advanced programming capabilities. Students learn how to handle unexpected errors gracefully and manage persistent data using files and multi-dimensional arrays.
Knowledge:
- The theoretical concept and necessity of exception handling in robust software.
- The mechanics and limitations of random number generation.
- The structural definition of single and multi-dimensional arrays, fields, records, and abstract data types.
Skills:
- Writing try/catch exception handling blocks to prevent program crashes.
- Storing, searching, and manipulating data inside 2D arrays (matrices).
- Opening, reading, writing, and appending data to external text and binary files using C# code.
How you can help at home:
- Act as the “Beta Tester”: Offer to test the software they write for class. Try to intentionally break it—type your name when the program asks for your age. This teaches them how to write robust “exception handling” code that does not crash when a user makes a mistake.
- File System Logic: Discuss how your family organises digital files (e.g., important documents vs. holiday photos). Ask them to explain how they would represent that folder structure using “Multi-dimensional arrays” or “Records” in C#.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of advanced programming capabilities and file handling. Past paper questions will be a mix of short answer, logic tracing, and longer coding-based questions. Additionally, your child will have two summative assessment assessing all content taught to date. Past paper questions will be a mix of ‘shade the lozenge’, short answer and longer answer coding/written questions. This should be read in conjunction with the AQA subject content within the specification.
Unit 10: The Internet
This unit demystifies the Internet. Students study the precise mechanics of how data travels globally, examining network layers, IP addressing, and robust internet security.
Knowledge:
- The 4-layer TCP/IP stack (Application, Transport, Network, Link) and their protocols (HTTP, HTTPS, FTP, SSH, SMTP, POP3, IMAP).
- The structure of IPv4 and IPv6 addresses, including public vs. private IPs and subnet masking.
- The roles of DNS, DHCP, Network Address Translation (NAT), and Port Forwarding.
- Client-server architecture, thin vs. thick client computing, and symmetric/asymmetric encryption.
Skills:
- Calculating subnet masks and network identifiers.
- Explaining packet switching and router forwarding processes.
- Evaluating network vulnerabilities and firewall configurations.
How you can help at home:
- Become Network Detectives: Have your child open the Command Prompt (Windows) or Terminal (Mac) on a home computer and type tracert bbc.co.uk. Ask them to explain the list of “hops” (routers) that appear on the screen.
- Router Configuration: Log into your home router together (usually by typing 192.168.1.1 into a web browser). Have them identify your DHCP settings, NAT configurations, and explain why your internal household devices all share one public IP address.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of the Internet, protocols, and network security. Past paper questions will be a mix of ‘shade the lozenge’, short answer calculations, and longer written questions.
Unit 13B: Design (NEA)
This unit focuses on planning the architecture, data structures, and user interface of the software solution before writing code.
Knowledge:
- Architectural structure and interface design principles.
- UML, flowchart, and pseudocode documentation standards.
Skills:
- Articulating a complete software design.
- Creating wireframes and mock-up screenshots.
- Documenting planned algorithms and data structures.
How you can help at home:
- The “Design Review”: Have them walk you through their user interface mock-ups on paper. Ask questions like “Where do I click to save?” to test usability before they code.
AQA Specification:
Links:
Assessments:
Your child’s written report will be internally assessed and externally moderated against the AQA Level of Response mark scheme for ‘Documented Design’, worth a maximum of 12 marks. Top marks require a fully articulated design of all key aspects.
Unit 8A: Algorithms 1
This unit introduces recursion, a powerful algorithmic technique where a function calls itself to solve smaller instances of a problem, significantly optimising code.
Knowledge:
- The theoretical definition of recursive techniques and base cases.
- The advantages and memory implications (e.g., stack overflow) of recursion compared to standard iteration (loops).
Skills:
- Identifying the base case and the recursive step within algorithms.
- Writing fully functioning recursive subroutines in C#.
- Tracing the execution of recursive calls via stack frames to determine the final output.
How you can help at home:
- Physical Recursion: Grab a set of Russian nesting dolls or ask them to draw a fractal (like a tree where every branch splits into two smaller branches). Have them explain the concept of the “base case”—the exact moment the dolls stop opening, or the tree stops branching.
- Code Tracing on Paper: Ask them to explain a recursive function to you by drawing the “Stack Frames” on a piece of paper. Having them physically draw how the computer’s memory builds up and then collapses helps cement a very abstract concept.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz to evaluate their understanding of recursive algorithms. (Please note, there is no summative assessment for this specific unit, as recursion is heavily tested in the later data structures and algorithm units).
Term 3
Unit 12A: Object-Oriented Programming (OOP)
This unit introduces the Object-Oriented Programming paradigm. Students will learn to structure their code around data “objects” rather than sequential procedures, mimicking real-world system architecture.
Knowledge:
- The distinct differences between procedural, object-oriented, and functional programming paradigms.
- The core OOP principles: classes, objects, instantiation, encapsulation, and inheritance.
- The concepts of polymorphism, aggregation, and composition in system design.
Skills:
- Designing UML class diagrams to model software systems.
- Writing C# code to define classes with private attributes and public methods.
- Implementing inheritance hierarchies and overriding base methods to create reusable software.
How you can help at home:
- Categorise the House: Ask your child to define the family pets, cars, or appliances using OOP logic. For example, a generic ‘Appliance’ class has a “Turn On” method, but the ‘WashingMachine’ subclass inherits that and adds a “Spin Cycle” method.
- Video Game Logic: If they play video games, ask them to explain how OOP is used to spawn enemies. For example, a base ‘Enemy’ class has ‘Health’, and a ‘Dragon’ subclass inherits that and adds ‘Breathe Fire’.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of the Object-Oriented Programming paradigm. Past paper questions will be a mix of short answer, UML diagrammatic, and longer coding-based questions.
Unit 11: Databases and Software Development
Students learn how to design, manage, and query relational databases. This unit also introduces the software development lifecycle essential for their NEA project.
Knowledge:
- Conceptual data modelling and entity-relationship diagrams (one-to-one, one-to-many, many-to-many).
- Database design principles, primary/composite/foreign keys, and Normalisation (1NF, 2NF, 3NF).
- The syntax and purpose of Structured Query Language (SQL) and concurrent access control.
- The stages of systematic problem solving: Analysis, Design, Implementation, Testing, and Evaluation (Agile vs Waterfall).
Skills:
- Normalising unorganised data into Third Normal Form (3NF) to eliminate data redundancy.
- Writing complex SQL statements (SELECT, UPDATE, INSERT, DELETE, JOIN) to interrogate databases.
- Executing a structured software development lifecycle to plan an independent coding project.
How you can help at home:
- Step in as “Project Manager”: Your child is completing their NEA (a massive independent project). Help them set up a Kanban board (using Trello, or sticky notes on the fridge) with “To Do,” “Doing,” and “Done” columns. Ask them every Sunday what their sprint goal is for the week.
- Database the Kitchen: Look at your kitchen cupboard. Ask your child how they would design a “Relational Database” to track what is there. Have them define the ‘Primary Keys’ (e.g., Barcode) and the ‘Attributes’ (e.g., Expiry Date, Brand).
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of relational databases and the software development lifecycle. Past paper questions will be a mix of short answer, SQL coding, and longer written design questions.
Unit 7A: Data Structures 1
Students are introduced to Abstract Data Types. They will learn how to organise data efficiently in memory, which is critical for writing high-performance algorithms.
Knowledge:
- The distinction between static and dynamic data structures.
- The logical properties and operational mechanics of Queues (linear, circular, priority) and Stacks.
- The structure of Trees, specifically binary trees, and node terminology.
- The role of stack frames in subroutine calls and recursive execution.
Skills:
- Pushing, popping, and peeking data within Stack structures.
- Enqueuing and dequeuing data within linear and circular Queues.
- Traversing binary trees and applying structural logic to data storage problems.
How you can help at home:
- Visualise with Household Items: Use physical items to demonstrate data structures. A stack of plates in the cupboard is a “Stack” (Last-In, First-Out). The family waiting at the supermarket checkout is a “Queue” (First-In, First-Out).
- The “Undo” Button: When using a word processor, press the “Undo” button a few times. Ask your child to explain how the software is using a “Stack” data structure to remember the exact order of your previous actions.
AQA Specification:
Links:
Assessments:
Your child will have a mid-point multiple-choice quiz and a summative assessment (made up of past paper examination questions) to evaluate their understanding of fundamental abstract data types and memory organization. Past paper questions will be a mix of short answer, diagrammatic, and longer coding or algorithmic questions. Additionally, your child will have two summative assessment assessing all content taught to date. Past paper questions will be a mix of ‘shade the lozenge’, short answer and longer answer coding/written questions. This should be read in conjunction with the AQA subject content within the specification.
