Computer ScienceQ&A by dot point

Follow and write algorithms (flowcharts, pseudocode, program code) that use sequence, selection, repetition (count-controlled, condition-controlled) and iteration with input, processing and output, and that use variables, constants and one- and two-dimensional data structures (strings, records, arrays).

Understand the benefit of using decomposition and abstraction to model aspects of the real world and to analyse, understand and solve problems, and understand the benefits of using subprograms.

Understand syntax, logic and runtime errors and correct logic errors in algorithms; understand how the standard algorithms (bubble sort, merge sort, linear search, binary search) work; and use logical reasoning and test data to evaluate an algorithm's fitness for purpose and efficiency.

Follow and write algorithms that use arithmetic operators (addition, subtraction, division, multiplication, modulus, integer division, exponentiation), relational operators (equal to, less than, greater than, not equal to, less than or equal to, greater than or equal to) and logical operators (AND, OR, NOT).

Determine the correct output of an algorithm for a given set of data, and use a trace table to determine what value a variable will hold at a given point in an algorithm.

Apply logical operators (AND, OR, NOT) in truth tables with up to three inputs to solve problems.

Understand the concept of an embedded system and what embedded systems are used for.

Understand the purpose and functionality of an operating system (file management, process management, peripheral management, user management).

Understand the characteristics and purposes of low-level and high-level programming languages, and how an interpreter differs from a compiler in the way it translates high-level code into machine code.

Understand the role of secondary storage and the ways in which data is stored on devices (magnetic, optical, solid state).

Understand the purpose and functionality of utility software (file repair, backup, data compression, disk defragmentation, anti-malware), and the importance of developing robust software and methods of identifying vulnerabilities (audit trails, code reviews).

Understand the von Neumann stored program concept and the role of main memory (RAM), the CPU (control unit, arithmetic logic unit, registers), the clock and the address, data and control buses in the fetch-decode-execute cycle.

Understand that computers use binary to represent data (numbers, text, sound, graphics) and program instructions, and determine the maximum number of states that can be represented by a binary pattern of a given length.

Add together two positive binary patterns, apply logical and arithmetic binary shifts, and understand the concept of overflow in relation to the number of bits available to store a value.

Understand how computers encode characters using 7-bit ASCII.

Understand that data storage is measured in binary multiples (bit, nibble, byte, kibibyte, mebibyte, gibibyte, tebibyte), construct expressions to calculate file sizes and data capacity, and understand the need for and methods of compression (lossless, lossy).

Understand why hexadecimal notation is used and convert between hexadecimal and binary.

Understand how bitmap images are represented in binary (pixels, resolution, colour depth), how analogue sound is represented in binary (amplitude, sample rate, bit depth, sample interval), and the limitations of binary representation when constrained by the number of available bits.

Understand how computers represent and manipulate unsigned integers and two's complement signed integers, and convert between denary and 8-bit binary numbers (0 to 255, and -128 to +127).

Understand ethical and legal issues associated with artificial intelligence, machine learning and robotics (accountability, safety, algorithmic bias, legal liability), and methods of intellectual property protection (copyright, patents, trademarks, licencing).

Understand the threat to digital systems posed by malware (viruses, worms, Trojans, ransomware, key loggers), how hackers exploit technical vulnerabilities and use social engineering, and methods of protecting digital systems and data (anti-malware, encryption, acceptable use policies, backup and recovery).

Understand environmental issues associated with the use of digital devices (energy consumption, manufacture, replacement cycle, disposal).

Understand ethical and legal issues associated with the collection and use of personal data (privacy, ownership, consent, misuse, data protection).

Understand the role of and need for network protocols (Ethernet, Wi-Fi, TCP/IP, HTTP, HTTPS, FTP) and email protocols (POP3, SMTP, IMAP).

Understand the importance of network security, ways of identifying network vulnerabilities (penetration testing, ethical hacking) and methods of protecting networks (access control, physical security, firewalls).

Understand why computers are connected in a network and understand the different types of networks (LAN, WAN).

Understand how the four-layer (application, transport, internet, link) TCP/IP model handles data transmission over a network, and understand the characteristics of network topologies (bus, star, mesh).

Understand how the internet is structured, including IP addressing and routers.

Understand how the characteristics of wired and wireless connectivity impact on performance (speed, range, latency, bandwidth), that network speeds are measured in bits per second, and construct expressions involving file size, transmission rate and time.

Write programs that make appropriate use of primitive data types (integer, real, Boolean, char) and one- and two-dimensional structured data types (string, array, record), and that make appropriate use of variables and constants.

Use decomposition and abstraction to solve problems; read, write, analyse and refine programs; convert algorithms (flowcharts, pseudocode) into programs; use techniques (layout, indentation, comments, meaningful identifiers, white space) for readable code; identify, locate and correct logic, syntax and runtime errors; and evaluate a program's fitness for purpose and efficiency.

Write programs that accept and respond appropriately to user input, and that read from and write to comma separated value text files.

Identify the structural components of programs (constants, variables, initialisation, assignment, sequence, selection, repetition, iteration, data structures, subprograms, parameters, input/output) and write programs that use sequencing, selection, repetition (count-controlled, condition-controlled) and iteration with single entry and exit points.

Write programs that manipulate strings (length, position, substrings, case conversion).

Write programs that use pre-existing and user-devised subprograms (procedures, functions), write functions that return values and procedures that do not, with or without parameters, use the arithmetic, relational and logical operators, and use global and local variables appropriately.

Understand the need for and write programs that implement validation (length check, presence check, range check, pattern check) and authentication (ID and password, lookup).