AEAIT Task 2 Cheatsheet

25/11/2025

Ultimate AIT Exam Cheatsheet

A concise, well-formatted revision sheet for AIT Task 2. HTML highlights are preserved using span tags and tables are converted to clean Markdown. Each point is on its own line for readability.

1. Data Organization & Best Practices

Definition: The process of sorting raw data into categories and arranging it logically so data is accessible, high-quality, and protected.

The three key systems

Day-to-Day System
- Purpose: For everyday file creation and current projects.
- Location: Local hard drive, USB, or cloud.
- Structure: Organize by project and type (e.g., /Project/Images/Docs).
Archive System
- Purpose: Store old or completed work that is important but not actively needed.
- Benefit: Keeps the Day-to-Day system uncluttered and fast.
Backup System
- Purpose: Redundant copies of Day-to-Day and Archive systems.
- Goal: Protect against data loss (corruption, theft, hardware failure).

Best practices (How-to)

Systematic naming
- Example: ProjectName_Type_YYYY-MM-DD_v01.ext (e.g., Science_LabReport_2025-11-25_v02.docx).
- Use underscores instead of spaces.
- Use ISO dates (YYYY-MM-DD).
- Keep names descriptive.
Version control
- Never overwrite raw data.
- Always work on a copy or use version control (Git) for text/code.
- Save new versions with incrementing numbers (v01, v02) or clear commit messages.
Data dictionary
- Maintain a document that standardizes category names, abbreviations, and allowed values.
Electronic housekeeping
- Schedule regular cleanups: remove duplicates, archive finished projects, update indexes.
Web rules
- Keep index.html or index.php in web root folders.
- Prefer plain text formats (.txt, .csv) for long-term archival to avoid obsolescence.

Metadata (data about data)

Definition: Data that provides information about other data.
Examples: Date created.
Examples: Camera model.
Examples: GPS location.
Examples: Author.
Examples: File size.
Uses: Search, sort, and filter files (e.g., “Find photos from Paris 2024”).
Tools: ExifTool (editing).
Tools: Hazel / DropIt (automation).

2. Graphics: Raster vs Vector

Raster (bitmap)

Building block: pixels (tiny coloured squares).
Scalability: Low — pixelates when enlarged.
File size: Typically larger (stores per-pixel data).
Best for: Photographs and images with complex colour gradients.
Conversion: Raster → Vector is hard (requires image tracing).

Vector

Building block: mathematical formulas (points, lines, curves).
Scalability: Infinite — no quality loss when resized.
File size: Often smaller (stores math/instructions).
Best for: Logos, fonts, icons, technical drawings.
Conversion: Vector → Raster is straightforward (export).

Key vocabulary

Pixel: Picture element — smallest unit of an image.
Bit depth: How many colours can be represented (1-bit = 2 colours; 24-bit ≈ 16.7M colours).
Anti-aliasing: Smooths jagged edges in raster images.
Rendering: Computing a drawable image from a model.

3. Comprehensive File Formats Guide

A compact reference for common formats and typical use cases.

Ext	Full name / Acronym	Type	Key notes / strengths	Typical use
.jpg	Joint Photographic Experts Group (JPEG)	Raster	Lossy compression; good for photos; no transparency	Digital photos, web images
.png	Portable Network Graphics (PNG)	Raster	Lossless; supports transparency (alpha)	Web graphics, logos with clear bg
.gif	Graphics Interchange Format (GIF)	Raster	Lossless (LZW); supports simple animation; 256-colour max	Simple animations, icons, memes
.tif	Tagged Image File Format (TIFF)	Raster	High-quality; often used for print/scanning; lossless options	Professional printing, archiving
.bmp	Bitmap	Raster	Simple/legacy; often uncompressed	Windows icons, simple images
.psd	Photoshop Document	Raster	Adobe native; retains layers and history	Editing work-in-progress
.svg	Scalable Vector Graphics (SVG)	Vector	XML-based; interactive; scalable	Responsive web graphics, vectors
.ai	Adobe Illustrator (AI)	Vector	Proprietary vector format	Logo and print design
.cgm	Computer Graphics Metafile (CGM)	Vector	Standard for technical diagrams	Engineering/technical graphics
.mp3	MPEG-1 Audio Layer 3 (MP3)	Audio	Lossy compression for audio	Streaming, sharing
.wav	Waveform Audio File Format (WAV)	Audio	Uncompressed, lossless audio	Studio recordings, editing
.wma	Windows Media Audio (WMA)	Audio	Microsoft format; lossy and lossless variants	Windows ecosystem playback

4. Audio Deep Dive: WAV vs MP3

(Based on Image 5262.png)

Feature	.wav (Waveform)	.mp3 (MPEG-1 Audio Layer 3)
Type	Uncompressed (raw)	Compressed (lossy)
Compression	Lossless (no quality loss)	Lossy (data removed)
Quality	Studio / original	Reduced depending on bitrate
File size	Large (~10 MB per minute typical)	Small (~1 MB per minute typical)
Best for	Editing, archiving, production	Streaming, distribution

5. Compression: Lossy vs Lossless

Lossy

Concept: Permanently deletes “unnecessary” data to reduce file size (e.g., sounds humans can’t hear, colours indistinguishable to the eye).
Pros: Huge space savings (often 5–10x smaller).
Cons: Irreversible quality loss; visible/audible artefacts if over-compressed.
Formats: JPEG, MP3, MP4, MPEG.

Lossless

Concept: Compresses data without deleting information (files can be fully restored).
Pros: 100% quality retention.
Cons: Larger file sizes than lossy.
Formats: PNG, GIF, TIFF, FLAC, ZIP.

6. Spreadsheet Functions: HLOOKUP & VLOOKUP

VLOOKUP (Vertical Lookup)

Definition: Searches for a value in the first column of a table array and returns a value in the same row from a specified column.
Syntax: =VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup])
When to use: When data is arranged in columns (e.g., ID in Column A and Price in Column B).

HLOOKUP (Horizontal Lookup)

Definition: Searches for a value in the first row of a table array and returns a value in the same column from a specified row.
Syntax: =HLOOKUP(lookup_value, table_array, row_index_num, [range_lookup])
When to use: When data is arranged in rows (headers on the top and data to the right).

Tip

Use INDEX/MATCH or XLOOKUP (if available) for more robust and flexible lookups.

7. Software Management & Licensing

Installation vs Update

Installation: Putting the software on the OS (via .exe, .dmg, or App Store).
Update: Post-install improvements — primarily for Security Patches, but also feature and bug fixes.

Software license types

License	Definition	Examples
Proprietary	Closed source. Owned by a company; paid use	Windows, Adobe CC, MS Office
Freeware	Free to use; closed source (no modifications)	Chrome, Skype, Adobe Reader
Open source	Source code is public; can modify/redistribute	Linux, Firefox, VLC, Moodle
Shareware	Proprietary software distributed as a trial	Various trial applications

Types of shareware

Demoware: Trial with limited time or features.
Adware: Free but displays advertisements.
Nagware: Full access but persistent payment prompts.
Donationware: Free, asks for voluntary donations.
Freemium: Basic features free; pay for premium features.

8. “For You To Do” — Model Answers

Use these model answers to respond to revision questions.

Q1: Explain your system of data organisation

“My data organisation strategy relies on three distinct systems:

Day-to-Day System: I use a structured folder hierarchy on my laptop (e.g., /School/Year12/AIT) for current assignments.
Archive System: At the end of every term, I move completed projects to an external hard drive. This keeps my working device fast.
Backup System: I perform a weekly mirror backup of both systems to the cloud to prevent data loss from hardware failure.”

Q2: Explain how a large organisation would organise their data

“A large organisation would use a Data Dictionary to ensure standard naming conventions.

They would use server-based storage with strict permissions (e.g., only HR can see HR files).
They would separate live servers from archive storage and keep automated, versioned backups.
They would implement role-based access control and auditing.”

Q3: What is the purpose of data organisation

“The purpose is to ensure data is accessible to authorised people, accurate for decision-making (via version control), and secure from loss or misuse.

It improves productivity and reduces errors.”

Quick printable summary

Use three systems: Day-to-Day, Archive, Backup.
File naming: Project_Type_YYYY-MM-DD_v01.ext.
Never overwrite raw data; use versioning.
Raster = pixels (photos); Vector = math (logos).
JPEG = lossy photos; PNG = lossless + transparency; SVG = scalable vector.
WAV = lossless large audio; MP3 = lossy small audio.
Prefer INDEX/MATCH or XLOOKUP over VLOOKUP.
Keep software updated for security; understand license types.