Key term
Eduqas A-Level Computer Science A500QS
Data Structures: Arrays, Records and Hash Tables
Stacks, Queues, Linked Lists and Trees
Boolean Logic and Simplification
Algorithms, Pseudo-Code and Programming Constructs
Variables, Scope, Parameters and Identifiers
Recursion and Modular Programming
Sorting Algorithms
Searching and Shortest-Path Algorithms
Big O Notation and Algorithm Efficiency
Validation, Verification and Testing
Data Compression
Programming Paradigms and Computer Languages
Topic overviewProgramming paradigms and where each is usedProcedural programmingEvent-driven and visual programmingMark-up languagesObject-oriented programming: objects, classes and methodsAmbiguity in natural language and the standardisation of languagesBackus-Naur form and syntax diagramsHigh-level and low-level languages, and choosing one
Systems Analysis, Maintenance and Documentation
Topic overviewWaterfall, Agile and approaches to systems developmentThe feasibility study, budgets and time scalesMethods of investigationAbstraction, decomposition and data flow diagramsSelecting suitable hardware and softwareAcceptance testing and methods of changeoverPerfective, adaptive and corrective maintenanceBackup and recovery proceduresUser and maintenance documentation
System Design and Human-Computer Interaction
Software Engineering Tools and Translators
Topic overviewSoftware tools for the software engineering processSoftware packages in analysis, specification, design and testingIntegrated development environmentsDebugging toolsProgram version managementCompilers, interpreters and assemblersThe stages of compilationTranslation errors and execution errors
Computing, Society and the Law
Computer Architecture, the Processor and Assembly Language
Topic overviewHardware elements and how they are connectedVon Neumann architecture and the stored program conceptThe processor: control unit, ALU and registersTypes of memory: RAM, ROM and virtual memoryCache memory and locality of referenceThe fetch-execute cycle and its registersParallel processing and the limits to parallelisationAssembly language and executing a program
Input, Output and Secondary Storage
Topic overviewInput devices and how data is capturedOutput devices and how results are presentedChoosing input and output devices for a situationVoice input, dictation and voice print recognitionMagnetic, optical and solid state storageComparing secondary storage for a purposeDisc organisation, fragmentation and defragmentation
Networks, Protocols and the Internet
Topic overviewNetworks, LANs and WANsNetwork topologies and connection hardwareNetworking standards and the layered modelIP addressing, TCP and UDPApplication protocols: HTTP, FTP, SMTP, IMAP and DHCPHandshaking and establishing a connectionWireless hardware and wireless technologiesThe internet and connected mobile devices
Data Transmission and Network Performance
Topic overviewSerial and parallel transmissionSimplex, half duplex and full duplexMultiplexing and sharing a channelCircuit, message and packet switchingPackets, headers and packet contentsNetwork collisions and collision detectionRouting traffic on a networkCalculating transfer rates and lowest cost routes
Number Systems and Binary Arithmetic
Data Types, Characters and Floating Point
Topic overviewPrimitive data typesStorage requirements for each data typeASCII and standardised character setsUnicode and multilingual encodingFloating point form: mantissa and exponentConverting between real numbers and floating pointInteger and floating point comparedTruncation, rounding and accuracy
Files, Records and File Organisation
Topic overviewThe purpose of files in data processingFiles, records and fieldsFixed and variable length fields and recordsMaster files and transaction filesSerial and sequential file accessIndexed sequential access and multi-level indexesDirect access and hashing algorithmsOverflow handling and file reorganisationFile security, backups, generations and archiving
Databases, Normalisation and Entity Modelling
SQL, Big Data and Distributed Systems
Topic overviewQuery languages and the purpose of SQLCreating tables: CREATE TABLE, data types and keysRetrieving data with SELECT, FROM and WHEREComparison operators, IN, AND, OR and sub-queriesSorting, grouping and aggregate functionsInserting, updating, deleting and joining dataThe DBMS, the data dictionary and distributed databasesBig Data, data warehousing, data mining and predictive analytics
The Operating System and Its Modes
Topic overviewThe need for an operating system and the role of the kernelManaging peripherals, processes and memory protectionThe user interface and the layers between user and hardwareDirectory structures and file attributesUtility softwareBatch processing, real time control and real time transaction systemsTypes of operating system: single-user, multi-user, multi-tasking and multi-programmingDesigning an interface for different users and environments
Interrupts, Memory Management and Scheduling
Topic overviewWhat causes an interruptInterrupt handling and the interrupt service routineInterrupt priorities and how they are allocatedPartitioning main memoryMethods of data transfer between processor and devicesBuffers and double bufferingHigh level scheduling, processor and device allocationProcess states, time-slicing, polling and threading
Types of Software System
Data Security, Cryptography and Attack
Topic overviewOnline updating and the integrity of shared filesDangers of holding personal dataClerical procedures, access levels, passwords and write protectionCryptography: its purpose, and symmetric and asymmetric keysHashing, digital signatures and certificatesCaesar and Vernam ciphers and comparing cipher strengthBiometric technologies and their limitationsThreats, damage and contingency planningMalicious software, hacking and penetration testing
Algorithms, Pseudo-Code and Programming Constructs
- 7 subtopics
- 21 things to know
- Component 1
What Algorithms, Pseudo-Code and Programming Constructs covers
Algorithms, Pseudo-Code and Programming Constructs is examined in Component 1, Programming and System Development. It covers algorithms and how they are defined, pseudo-code conventions, Flowcharts and flowchart symbols, sequence and selection, repetition: count-controlled and condition-controlled loops, counts, totals and rogue values and tracing, altering and writing algorithms.
The 7 subtopics
Each one has its own page.
- Algorithms and how they are definedTerm algorithm, two common methods of defining an algorithm and efficiency of an algorithm.Open →
- Pseudo-code conventionsThe house notation for assignment, input, output, selection and repetition — what a written answer is expected to look like when no real language is named.Open →
- Flowcharts and flowchart symbolsThe terminator, process, decision, input/output and subprogram symbols, the arrows that join them, and reading an algorithm off a diagram.Open →
- Sequence and selectionNested IF, term condition and relational operators used in conditions.Open →
- Repetition: count-controlled and condition-controlled loopsCount-controlled loop, condition-controlled loop and infinite loop.Open →
- Counts, totals and rogue valuesCount in an algorithm, running total and term rogue value.Open →
- Tracing, altering and writing algorithmsDry run, desk check and first step in writing an algorithm for an unfamiliar problem.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What makes a loop run for ever, and what prevents it?
Key term
Define the term algorithm.
Key term
What is a flowchart?
Process
What is sequence?
Key term
What is a count in an algorithm?
Key term
What does tracing an algorithm by hand involve?
Key term
Name two common methods of defining an algorithm.
Key term
What is pseudo-code?
Key term
Which symbol shows the start or the end of a flowchart?
Process
Why does the order of a sequence matter?
Key term
What is repetition?
Key term
How is a count initialised and updated?
Key term
Why is a trace table used?
Key term
Why is an algorithm written before any code?
Key term
How is a value assigned to a variable in pseudo-code?
Process
Which symbol represents a process?
Key term
What is selection?
Key term
What is a count-controlled loop?
Key term
What is a running total?
Key term
What is a dry run?
Take Algorithms, Pseudo-Code and Programming Constructs further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Sequence vs Selection
Sequence: always running every step in order. Selection: running only the branch whose condition is true.
Count-controlled loop vs Condition-controlled loop
Count-controlled loop: repeating a known number of times. Condition-controlled loop: repeating until a test changes its result.
Count vs Running total
Count: recording how many values arrived. Running total: recording the sum of those values.
Questions from this topic
Each one with the model answer underneath.
- 1
Define the term algorithm.
Model answer
An algorithm is a precise sequence of steps that solves a problem or performs a task. Each step is unambiguous and the process comes to an end.
- 2
Name two common methods of defining an algorithm.
Model answer
An algorithm is commonly defined in pseudo-code or as a flowchart. Structured English is a third possibility.
- 3
Why is an algorithm written before any code?
Model answer
An algorithm sets out the logic independently of any programming language. Errors in the reasoning are found before coding begins.
- 4
What must be true of every algorithm with respect to ending?
Model answer
An algorithm must terminate after a finite number of steps. A process that never ends is not an algorithm.
- 5
Why must each step of an algorithm be unambiguous?
Model answer
An ambiguous step could be carried out in more than one way. Two people following the algorithm would then obtain different results.
- 6
Give one advantage of pseudo-code over a flowchart.
Model answer
Pseudo-code is quick to write and translates almost line for line into program code. A long algorithm also fits on far less paper.
What is inside Levo
Six ways to work the same material.
Algorithms, Pseudo-Code and Programming Constructs revision questions
- What does Algorithms, Pseudo-Code and Programming Constructs cover in Eduqas A-Level Computer Science?
- 7 subtopics: algorithms and how they are defined, pseudo-code conventions, flowcharts and flowchart symbols, sequence and selection, repetition: count-controlled and condition-controlled loops, counts, totals and rogue values and tracing, altering and writing algorithms. Each one has its own page with questions and model answers.
- How is Algorithms, Pseudo-Code and Programming Constructs organised?
- By the Eduqas A500QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Algorithms, Pseudo-Code and Programming Constructs, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.