OCR A-Level Computer Science Past Papers & Mark Schemes

OCR A-Level Computer Science (H446) is the most widely taken A-Level CS specification in England. It combines two written examinations — one on computer systems theory and one on algorithms and programming — with a substantial programming project that accounts for 20% of the final grade. Paper 1: Computer Systems (H446/01, 2 hours 30 minutes, 140 marks, 40%) covers the theoretical foundations of computing. Content includes: the characteristics of processors and their architecture (von Neumann, Harvard, CISC vs RISC); input, output, and storage devices; software classification (system software, utility programs, translators); data types and number systems (binary, hexadecimal, two's complement, floating point); data structures (arrays, linked lists, stacks, queues, trees, hash tables, graphs); Boolean algebra and logic gates; legal, moral, and ethical issues; and networking (TCP/IP, protocols, security). Paper 2: Algorithms and Programming (H446/02, 2 hours 30 minutes, 140 marks, 40%) focuses on problem-solving and algorithm design. Content includes: computational thinking (abstraction, decomposition, pattern recognition); algorithm design and complexity (Big O notation); searching algorithms (linear, binary); sorting algorithms (bubble, merge, insertion, quick sort); graph traversal (breadth-first, depth-first); Dijkstra's algorithm; object-oriented programming concepts (inheritance, polymorphism, encapsulation); functional programming (higher-order functions, map, filter, fold); and programming paradigms. The Programming Project (H446/03, NEA, 70 marks, 20%) requires students to design, develop, test, and evaluate a solution to a problem of their choice using a programming language. The project must demonstrate analysis, design, technical skill (including algorithms of appropriate complexity), and evaluation.