Know and understand file/data structures including field length, field name, data type, coding of data for example M for male, F for female

1. Computer Hardware

• Central Processing Unit (CPU) – the “brain” that executes instructions; characterised by clock speed (MHz/GHz) and number of cores.
• Memory (RAM) – temporary storage for data and programmes while they are running; measured in megabytes (MB) or gigabytes (GB).
• Primary storage devices

  • Hard‑disk drive (HDD) – magnetic platters, larger capacity, slower access.
  • Solid‑state drive (SSD) – flash memory, faster access, more reliable.

• Secondary storage media

  • Optical discs – CD, DVD, Blu‑ray (read‑only or write‑once).
  • USB flash drives, external hard drives.
  • Cloud storage – data kept on remote servers accessed via the Internet.

• Motherboard & bus architecture – connects CPU, RAM, storage and peripheral devices.
• Power supply & cooling – converts mains voltage, provides stable power; fans/heatsinks prevent overheating.

2. Input and Output (I/O) Devices

• Input devices

  • Keyboard, mouse, touchpad, graphics tablet.
  • Scanners, digital cameras, microphones.
  • Barcode readers, magnetic‑stripe readers, RFID scanners.

• Output devices

  • Monitors – CRT, LCD, LED, OLED (resolution, colour depth).
  • Printers – ink‑jet, laser, dot‑matrix; concepts of DPI (dots per inch).
  • Speakers, headphones, projectors.

• Combined I/O – touch screens, all‑in‑one printers, multifunction devices.

3. Storage Technologies

• Magnetic storage – HDDs, floppy disks, magnetic tapes.
• Optical storage – CD‑ROM, DVD‑R/W, Blu‑ray.
• Solid‑state storage – SSDs, USB flash drives, memory cards (SD, micro‑SD).
• Networked storage – NAS (Network‑Attached Storage), SAN (Storage Area Network), cloud services.
• File‑system concepts

  • Blocks/sectors, file allocation tables, fragmentation.
  • Common file‑system types: FAT, NTFS, ext4, HFS+.

4. Networks and the Internet

• Network types

  • LAN – Local Area Network (e.g., school or office).
  • WAN – Wide Area Network (e.g., the Internet).
  • MAN – Metropolitan Area Network.

• Network hardware

  • Router – directs traffic between networks.
  • Switch – connects devices within a LAN.
  • Modem – converts digital data to analogue signals for telephone lines or cable.
  • Access point – provides wireless connectivity (Wi‑Fi).

• Transmission media

  • Twisted‑pair cable (UTP, STP), coaxial cable, fibre‑optic cable.
  • Wireless – radio waves, microwaves, satellite links.

• Internet protocols (essential for the syllabus)

  • HTTP / HTTPS – web pages.
  • FTP – file transfer.
  • SMTP – e‑mail transmission.
  • TCP/IP – basic communication suite.

5. Effects of Information Technology

• Positive effects

  • Improved communication (e‑mail, video‑conferencing).
  • Increased productivity (automation, databases).
  • Access to information and education.

• Negative effects

  • Health issues – repetitive‑strain injury (RSI), eye strain, hearing loss.
  • Social concerns – cyber‑bullying, digital divide.
  • Environmental impact – e‑waste, energy consumption.

• Legal & ethical considerations – privacy, data protection, copyright, software piracy.

6. ICT Applications

• Communication – e‑mail, instant messaging, video‑calling, social media.
• Modelling & simulation – CAD for engineering, virtual labs, weather forecasting.
• Control systems – traffic‑light control, industrial PLCs, home automation.
• Banking & finance – ATMs, online banking, electronic payments.
• Medical & health – electronic patient records, diagnostic expert systems.
• Retail & e‑commerce – point‑of‑sale (POS) systems, online stores, barcode scanners.
• Expert systems & artificial intelligence – medical diagnosis, fault detection.
• Recognition technologies – facial recognition, fingerprint scanners.
• Satellite & GPS – navigation, remote sensing, weather satellites.

7. Systems Life Cycle (SLC)

The SLC provides a systematic framework for developing, implementing and maintaining an information system. Each stage must be completed and reviewed before moving to the next.

7.1 Analysis

• Purpose – understand the problem or opportunity and define system objectives.
• Requirements‑gathering techniques

  • Observation – watch users perform the current task.
  • Interview – ask open‑ended questions to individuals or groups.
  • Questionnaire – collect data from many users quickly.
  • Document review – study existing forms, reports and procedures.

• Outputs

  • System specification – inputs, outputs, processing, user requirements.
  • Feasibility study – technical, economic, legal, operational.

7.2 Design

• Design artefacts (Cambridge required)

  • File/Data structures – definition of records and fields.
  • Input formats – screen layouts, forms, data‑entry devices.
  • Output formats – report layouts, screen displays, printed forms.
  • Validation routines – type, range, length and format checks.

• Design considerations

  • Usability – logical screen flow, clear prompts.
  • Efficiency – minimise unnecessary processing or storage.
  • Security – user‑access levels, data‑protection measures.

7.3 Development & Testing

• Development – coding the system according to the design documents, using an appropriate programming language or configuration tool.
• Testing

  • Test plan – what will be tested, who will test, schedule.
  • Test data

    • Normal data – typical values.
    • Abnormal data – plausible but out‑of‑range values.
    • Extreme data – values at the limits of field definitions.

  • Test types

    • Module (unit) testing.
    • Integration testing.
    • System testing – against the specification.

  • Record results in a test report – pass/fail status, observed errors, corrective actions.

7.4 Implementation

• Implementation methods (Cambridge)

  • Direct change‑over – switch off the old system and start the new one immediately.
  • Parallel running – run old and new systems side‑by‑side for a period.
  • Pilot – introduce the system to a small, representative group first.
  • Phased – roll out the system in stages (e.g., by department).

• Key activities – installation, data migration, user training, post‑implementation support.

7.5 Documentation

• Technical documentation (for developers/maintainers)

  • System description and architecture diagram.
  • Flowcharts, pseudo‑code or UML diagrams.
  • Hardware and software specifications.
  • Database schema and file‑structure definitions.
  • API specifications (if applicable).

• User documentation (for end‑users)

  • Installation guide.
  • Operation manual – how to enter data, run reports, etc.
  • Troubleshooting checklist.
  • FAQ and help screens.
  • Glossary of terms.

7.6 Evaluation

• Evaluation criteria (Cambridge)

  • Efficiency – speed of processing and resource use.
  • Effectiveness – does it produce the required outputs?
  • Ease of use – user satisfaction, error rates.
  • Reliability – downtime, frequency of failures.
  • Security – protection of data and compliance with policies.

• Produce an evaluation report that summarises findings, identifies shortcomings and recommends further improvements.

8. Safety & Security

• Physical safety

  • Ergonomic workstation layout – chair height, monitor position.
  • Safe handling of hardware – unplug before maintenance.
  • Fire safety – keep fire‑extinguishers, avoid blocking exits.
  • Secure storage of removable media.

• E‑safety

  • Safe browsing – avoid suspicious links, use reputable browsers.
  • Phishing awareness – check sender address, never share passwords.
  • Antivirus & anti‑malware – keep definitions up‑to‑date.
  • Regular software updates and patches.

• Data protection

  • Back‑up strategy – full and incremental backups, off‑site storage.
  • Access control – passwords, user IDs, role‑based permissions, two‑factor authentication.
  • Encryption – SSL/TLS for data in transit, AES for data at rest.
  • Legislation – GDPR (EU) and UK Data Protection Act – rights of individuals, data‑controller responsibilities.

• Security threats & countermeasures

  • Malware – viruses, worms, ransomware – use anti‑malware software.
  • Unauthorised access – firewalls, intrusion‑detection systems.
  • Social engineering – education and verification procedures.
  • Denial‑of‑service (DoS) attacks – network monitoring and rate limiting.

9. Audience & Copyright

• Audience analysis

  • Identify users’ needs, prior knowledge, and expectations.
  • Tailor language, level of detail and presentation style accordingly.

• Copyright basics

  • Original works are automatically protected – you need permission to copy, adapt or distribute.
  • Common licences – proprietary, share‑ware, free‑ware, open‑source (e.g., GNU GPL).
  • Consequences of software piracy – legal action, fines, loss of reputation.

10. Communication (Email, Internet, Protocols & Evaluating Web Sources)

• E‑mail etiquette

  • Clear subject line, professional greeting, concise body.
  • Attach files appropriately, use “Reply‑All” sparingly.
  • Beware of spam and phishing – never open unexpected attachments.

• Internet use

  • Secure browsing – look for “https://” and the padlock icon.
  • Respect digital rights – no illegal downloading.

• Key protocols

  • HTTP / HTTPS – web page transfer.
  • FTP – file transfer.
  • SMTP / POP3 / IMAP – e‑mail sending and retrieval.
  • SSL / TLS – encryption of data in transit.

• Evaluating online information

  • Authority – who is the author or organisation?
  • Accuracy – cross‑check with other reliable sources.
  • Bias – is the information presented objectively?
  • Currency – when was it published or last updated?
  • Purpose – inform, persuade, sell, or entertain?

11. File Management

• File naming conventions – use meaningful, concise names; avoid spaces; use underscores or camelCase; include version numbers if needed.
• Folder hierarchy – organise files into logical folders (e.g., Projects/2025/Report_v2).
• File extensions – indicate format (e.g., .docx, .xlsx, .jpg).
• File properties – size, date created, date modified, author.
• Backup & recovery – regular copies on external media or cloud; test restore procedures.

12. Working with Images

• Image formats

  • Raster – BMP, GIF, JPEG, PNG (pixel‑based, resolution matters).
  • Vector – SVG, EPS (resolution‑independent, scalable).

• Basic editing tasks

  • Resize, crop, rotate.
  • Adjust brightness/contrast, colour balance.
  • Apply simple effects – borders, shadows.

• Resolution & DPI – 72 dpi for screen, 300 dpi for print; calculate pixel dimensions: pixels = inches × DPI.

13. Document Layout & Styles

• Page layout

  • Margins, orientation (portrait/landscape), columns.
  • Headers, footers, page numbers.

• Styles – predefined formatting for headings, body text, lists; ensures consistency and speeds up formatting.
• Templates – reusable document structures for letters, reports, newsletters.

14. Proof‑reading & Editing Tools

• Spell‑check and grammar check.
• Find & replace (including wildcards).
• Track changes – collaborative editing.
• Comments – feedback without altering the original text.

15. Graphs and Charts

• When to use which type

  • Bar chart – compare quantities across categories.
  • Line graph – show trends over time.
  • Pie chart – illustrate parts of a whole (use sparingly).
  • Scatter plot – display relationship between two variables.

• Key components – title, axes labels, scale, legend, data markers.
• Design tips – avoid clutter, use appropriate colours, label clearly.

16. Document Production (Word‑Processing)

• Creating, saving and printing documents.
• Using tables – insert, format, sort data.
• Inserting hyperlinks, bookmarks, cross‑references.
• Mail merge – generate personalised letters or labels from a data file.

17. Databases (Beyond File Structures)

• Database concepts

  • Table – collection of records (rows) with fields (columns).
  • Primary key – unique identifier for each record.
  • Foreign key – links related tables.

• SQL basics

  • SELECT – retrieve data.
  • INSERT – add new records.
  • UPDATE – modify existing records.
  • DELETE – remove records.

• Forms & reports – user‑friendly data entry screens and formatted output.

18. Presentations

• Slide design – use bullet points, limit text, high‑contrast colours.
• Inserting multimedia – images, audio, video, animations.
• Slide transitions and timing – keep them subtle.
• Speaker notes – private prompts for the presenter.

19. Spreadsheets

• Cells, rows, columns, worksheets.
• Formulas & functions – SUM, AVERAGE, IF, VLOOKUP, COUNTIF.
• Cell referencing – relative, absolute (\$A\$1) and mixed.
• Data visualisation – charts, conditional formatting.
• Sorting, filtering and pivot tables for data analysis.

20. Website Authoring

• HTML basics – tags for headings (<h1>), paragraphs (<p>), links (<a href="">), images (<img src="">).
• CSS basics – selectors, properties (colour, margin, font‑size) to control appearance.
• Using a WYSIWYG editor – drag‑and‑drop layout, then view the generated code.
• Publishing – upload files via FTP to a web server, test in multiple browsers.

21. Objective: File/Data Structures

A file (or database table) is made up of records. Each record contains one or more fields. Understanding the components of a field is essential for designing efficient storage and for ensuring data integrity.

Key Components of a Field

• Field Name – concise, descriptive identifier (e.g., FirstName).
• Field Length – maximum number of characters or bytes the field can hold.
• Data Type

  • Text / Character
  • Integer
  • Decimal (fixed‑point or floating‑point)
  • Date
  • Boolean (Yes/No, True/False)
  • Alphanumeric (mix of letters and numbers)

• Coding of Data – use a short code or single character to represent a value (e.g., M for Male, F for Female).

Example: Student Record Structure

Calculating Record Size

To estimate storage required for a single record, add the field lengths (in bytes). For character data, 1 character = 1 byte (ASCII). If Unicode is used, assume 2 bytes per character.

Example (ASCII): 8 + 20 + 25 + 1 + 10 + 4 + 1 = 69 bytes

Common Coding Schemes

• Gender: M = Male, F = Female, O = Other.
• Status: Y = Yes, N = No.
• Payment method: C = Cash, D = Debit, R = Credit.
• Priority: H = High, M = Medium, L = Low.

Best Practices for Designing Field Structures

1. Use clear, concise field names – avoid spaces; adopt CamelCase or snake_case.
2. Set field lengths just long enough for the expected maximum data; this saves storage and reduces input errors.
3. Choose the most appropriate data type – numeric types for calculations, text for free‑form entry, Boolean for true/false values.
4. Apply coding only when it reduces storage or simplifies processing; always provide a code‑key table.
5. Validate data entry against field definitions (type, range, length, format) to maintain data integrity.
6. Document the complete file structure in a data‑dictionary – include field name, length, type, allowed codes and a brief description.

Mastering these concepts enables you to design efficient, reliable databases and forms, which are essential components of the Design, Development and Testing phases of the Systems Life Cycle.