Home · GCSE · Computer Science · AQA
AQA
AQA GCSE Computer Science (8525)
Spec code 8525 · v2020 · valid from 2020
8 domains · 50 topics
Mastered In progress Not started Higher tier
CS1
Fundamentals of algorithms
4 topics- CS1.1Representing algorithms: pseudo-code, flowcharts, written descriptions; comparing algorithms for the same problem
- CS1.2Efficiency of algorithms: comparing algorithms by number of steps; recognising why one algorithm is more efficient than another
- CS1.3Searching algorithms: linear search and binary search; required preconditions and step-by-step traces
- CS1.4Sorting algorithms: bubble sort and merge sort; tracing each pass and comparing efficiency
CS2
Programming
12 topics- CS2.1Data types: integer, real (float), Boolean, character, string; choosing an appropriate type for given data
- CS2.2Programming concepts: variables, constants, assignment, sequence, selection (IF), iteration (WHILE, FOR), input/output
- CS2.3Arithmetic operations: addition, subtraction, multiplication, real division, integer division (DIV), modulus (MOD), exponentiation
- CS2.4Relational and Boolean operations: =, ≠, <, ≤, >, ≥; AND, OR, NOT; building compound conditions in selection and iteration
- CS2.5Data structures: 1D and 2D arrays (lists), records; choosing a structure to fit a problem
- CS2.6Input/output and file handling: reading from and writing to text files; reading user input and producing formatted output
- CS2.7String handling: length, position, substring, concatenation, conversion to upper/lower case and to ASCII values
- CS2.8Random number generation: using a built-in function to generate pseudo-random integers within a stated range
- CS2.9Subroutines (procedures and functions): parameters and return values; local vs global variables; benefits of using subroutines
- CS2.10Structured programming and structured programming techniques: top-down design, modularity, abstraction, decomposition
- CS2.11Robust and secure programming: validation, authentication, defensive programming, anticipating misuse and edge cases
- CS2.12Classification of programming languages and translators: high-level vs low-level; assemblers, compilers and interpreters
CS3
Fundamentals of data representation
8 topics- CS3.1Number bases: decimal (denary), binary and hexadecimal; counting in each base
- CS3.2Converting between number bases: 8-bit unsigned binary ↔ denary; binary ↔ hexadecimal; denary ↔ hexadecimal
- CS3.3Units of information: bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte using the 1024 prefix
- CS3.4Binary arithmetic: addition of two 8-bit numbers; binary shifts (left/right) and their multiplicative effect; overflow
- CS3.5Character encoding: ASCII (7-bit) and Unicode; representing text as a sequence of integer codes; comparing range and storage cost
- CS3.6Representing images: pixels, resolution, colour depth; calculating file size = width × height × bits-per-pixel ÷ 8
- CS3.7Representing sound: analogue waveform sampled at a rate (Hz) and bit depth; file size = sample rate × duration × bit depth
- CS3.8Data compression: lossy vs lossless; benefits, drawbacks and choosing the right compression for a use case
CS4
Computer systems
8 topics- CS4.1Hardware and software: how each is defined; relationship between them; embedded systems
- CS4.2Boolean logic: AND, OR, NOT gates; logic circuit diagrams and truth tables; constructing simple expressions and simplification
- CS4.3Software classification: system software (OS, utilities), application software; examples and main jobs of an OS
- CS4.4Operating systems: functions — process management, memory management, file management, peripheral management, security and user interface
- CS4.5Utility programs: encryption, defragmentation, data compression, backup; how each helps maintain a working system
- CS4.6Stored program / von Neumann architecture: CPU, main memory, address & data buses; the fetch–decode–execute cycle
- CS4.7CPU components and registers: ALU, control unit, registers (PC, MAR, MDR, accumulator); CPU performance — clock speed, cache, cores
- CS4.8Memory: RAM vs ROM; volatile vs non-volatile; cache and virtual memory; secondary storage — magnetic, optical and solid-state
CS5
Fundamentals of computer networks
6 topics- CS5.1Networks and types: LAN vs WAN; client–server vs peer-to-peer; benefits and drawbacks of networking computers
- CS5.2Wired and wireless connectivity: copper, fibre, Wi-Fi, Bluetooth; comparing speed, range, cost and reliability
- CS5.3Network topologies: star and mesh (full and partial); diagrams and pros/cons of each
- CS5.4Protocols: TCP/IP stack; HTTP, HTTPS, FTP, SMTP, IMAP, IP, TCP, UDP, Ethernet and Wi-Fi protocols
- CS5.5Network security: encryption (asymmetric and symmetric), firewalls, MAC address filtering and authentication; layers of defence
- CS5.6The 4-layer TCP/IP model: application, transport, network and link layers; what each layer does and example protocols
CS6
Cyber security
5 topics- CS6.1Cyber-security threats: malicious code, weak/default passwords, misconfigured access rights, removable media, unpatched software
- CS6.2Social engineering: blagging, phishing, pharming, shoulder surfing; how the attacker exploits human behaviour
- CS6.3Malicious code (malware): viruses, worms, Trojans, spyware, ransomware; how they spread and what each one does
- CS6.4Detecting and preventing cyber-security threats: biometrics, password systems, CAPTCHA, email confirmation, automatic software updates
- CS6.5Penetration testing: white-box (tester has knowledge) vs black-box (tester does not); purpose and limits
CS7
Relational databases and Structured Query Language (SQL)
3 topics- CS7.1Relational databases: tables, records, fields, primary and foreign keys, relationships; entity-relationship diagrams
- CS7.2SQL — SELECT statements: SELECT … FROM … WHERE …; using AND/OR; ORDER BY; selecting columns and filtering rows
- CS7.3SQL — INSERT, UPDATE, DELETE: adding new rows, changing existing rows and removing rows; effect on referential integrity
CS8
Ethical, legal and environmental impacts of digital technology
4 topics- CS8.1Ethical issues: AI bias, censorship, privacy intrusions, the digital divide; weighing benefits to society against harm
- CS8.2Legal issues and key UK legislation: Data Protection Act 2018, Computer Misuse Act 1990, Copyright Designs and Patents Act 1988, Creative Commons
- CS8.3Environmental issues: energy use of data centres, e-waste, manufacture and disposal of devices; mitigations and circular-economy ideas
- CS8.4Privacy issues: tracking, profiling, biometric data, the right to be forgotten; informed consent and lawful data sharing