GCSE Computer Science practice, marked as they go.

1. 1Computational Thinking and Problem Solving+

   • Break problems down using decomposition
   • Remove unnecessary detail through abstraction
   • Identify patterns and design step-by-step algorithmic solutions
   • Understand inputs, processes and outputs
   • Represent solutions using flowcharts, pseudocode and trace tables
   • Interpret, complete, correct and refine algorithms
   • Understand the importance of logical structure, precision and systematic problem-solving
2. 2Systems Architecture, Memory, Storage and System Software+

   • Understand the purpose of the CPU and the fetch-execute cycle
   • Understand the role of the ALU, control unit, cache and registers
   • Explain the factors affecting CPU performance: clock speed, cache size and number of cores
   • Understand embedded systems
   • Understand primary storage: RAM, ROM, cache and virtual memory
   • Compare secondary storage devices and media in terms of capacity, speed, portability, durability, reliability and cost
   • Understand how operating systems manage memory, files, peripherals, users and multitasking
   • Understand how utility software supports encryption, compression and defragmentation
3. 3Computer Networks, Connections, Protocols and Network Security+

   • Compare LANs and WANs and the factors that affect network performance
   • Understand the role of network hardware: routers, switches, wireless access points, NICs and transmission media
   • Understand client-server and peer-to-peer networks, the internet, DNS, hosting, cloud computing, web servers and clients
   • Compare star and mesh topologies and evaluate wired and wireless connections
   • Understand protocols: TCP/IP, HTTP, HTTPS, FTP, POP, IMAP and SMTP
   • Understand IP and MAC addressing, encryption and the concept of layers
   • Understand threats to networks: malware, social engineering, brute-force attacks, denial-of-service attacks, data interception and SQL injections
   • Evaluate prevention methods: firewalls, anti-malware, penetration testing, user access levels, passwords, encryption and physical security
4. 4Binary Data Representation and Boolean Logic+

   • Understand why computers use binary and convert between binary, denary and hexadecimal
   • Perform binary addition, identify overflow errors and understand the effect of binary shifts
   • Know the data units: bits, nibbles, bytes, kilobytes, megabytes, gigabytes, terabytes and petabytes, and calculate data capacity requirements
   • Understand how characters are represented using character sets such as ASCII and Unicode
   • Understand how images are represented using pixels, colour depth and resolution
   • Understand how sound is represented using sample rate, duration and bit depth
   • Understand compression, including lossy and lossless methods
   • Use AND, OR and NOT gates, complete truth tables and solve logic problems involving combined gates
5. 5Searching, Sorting and Algorithms+

   • Understand how linear search and binary search work, including that binary search needs an ordered list
   • Understand bubble sort, insertion sort and merge sort, including the main steps of each
   • Trace searching and sorting algorithms using data sets
   • Identify an algorithm from code, pseudocode or OCR Exam Reference Language
   • Compare when different algorithms may be appropriate
   • Explain how algorithms process data step by step
   • Complete and correct algorithms and use trace tables in exam-style questions
6. 6Ethical, Legal, Cultural and Environmental Impacts of Digital Technology+

   • Understand the impact of digital technology on individuals, organisations and society
   • Discuss ethical, legal, cultural, environmental and privacy issues linked to technology use
   • Know the Data Protection Act 2018, the Computer Misuse Act 1990 and the Copyright, Designs and Patents Act 1988
   • Compare software licences: open-source and proprietary software
   • Apply knowledge of systems, networks, security, data and programming to real-world issues: privacy, cybercrime, environmental impact, the digital divide, artificial intelligence, data collection and responsible technology use
   • Write balanced, extended responses using evidence and examples
7. 7Producing Robust Programs+

   • Develop reliable and maintainable software through validation, verification, authentication and defensive design
   • Create test plans using normal, boundary, invalid and erroneous test data
   • Refine solutions through testing
8. 8Programming Techniques and IDEs+

   • Develop larger programs using arrays, file handling, SQL, records, functions, procedures and random numbers
   • Understand how IDEs support software development
   • Investigate interpreters and compilers
9. 9GCSE Retrieval, Consolidation and Examination Preparation+

   • Revise all Paper 1 and Paper 2 content through a structured revision programme
   • Revisit misconceptions and complete retrieval activities
   • Undertake mock examinations
   • Practise extended-response and OCR reference language questions
   • J277/01 Computer systems: written paper, 1 hour 30 minutes, 50% of the GCSE, 80 marks, non-calculator
   • J277/02 Computational thinking, algorithms and programming: written paper, 1 hour 30 minutes, 50% of the GCSE, 80 marks, non-calculator

Topics follow the OCR J277 specification. PrepAcer is independent and not affiliated with the exam board.