lesson 08 - factors affecting ui choice 2 - requirements & storage
This page covers the crucial factors of user requirements—what the interface must do and how well it must do it—and how the simple constraint of storage space can dramatically affect UI design choices.
Before a single line of code is written or a pixel is placed, a designer must understand the rules of the game. In UI design, these rules are called user requirements. They are the blueprint for a successful project, defining what the client needs and what the user expects. Alongside this, a very practical consideration can make or break a project: storage.
Learning Outcomes
The Building Blocks 🧱 (Factual Knowledge)
The Connections and Theories 🔗 (Conceptual Knowledge)
The Skills and Methods ⛏️ (Procedural Knowledge)
Recall that user experience refers to the overall feeling a person has when using an interface.
Describe how accessibility is a key factor in ensuring an interface can be used by people with a wide range of abilities.
Describe how storage space can be a limiting factor in the choice of a user interface, particularly on low-powered or embedded devices.
The Connections and Theories 🔗 (Conceptual Knowledge)
Describe how the user experience of 'The Majestic Cinema' project will be shaped by the choice of colours, fonts, and layout.
Analyse the importance of considering accessibility from the start of the project, explaining how it relates to the diverse audience of the cinema.
Evaluate the trade-offs between a visually rich interface with large graphics (requiring more storage) and a simpler, faster-loading interface for the Majestic Cinema's website.
Skill Focus: Digital Project Management: Creating project plans.
The Skills and Methods ⛏️ (Procedural Knowledge)
Apply project management principles to break down the development of the 'Facilities & Accessibility' screen into a list of smaller, manageable tasks.
Apply knowledge of project constraints to identify the key requirements and limitations that will affect the UI choice for the Majestic Cinema.
Create a simple project plan or task list for the initial design phase of the Majestic Cinema project, identifying key tasks and ordering them logically.
✅ What are User Requirements?
User requirements are a formal list of the functions and characteristics that a user interface must have. Getting these right is the most important step in any project. We split them into two distinct categories:
1
Functional Requirements (What it DOES)
These are the essential actions the interface must be able to perform. They are the 'verbs' of the project. If a functional requirement is not met, the project is a failure.
For our Majestic Cinema project, examples include:
The system must allow users to view a list of films currently showing.
The system must provide a way to book tickets.
The system must display information about the cinema's facilities.
2
Non-Functional Requirements (HOW WELL it does it)
These requirements don't describe an action, but a quality, constraint, or characteristic of the interface. They are the 'adjectives' that define the user experience.
For our Majestic Cinema project, examples include:
The layout must be consistent across all four screens.
The language used must be clear and easy to understand.
The ticket booking process must be simple and intuitive.
The design must be accessible to users with disabilities.
💾 The Storage Factor
It's easy to forget, but every digital asset—every image, every video, every font, every line of code—takes up physical storage space on a device. The combined size of these assets determines the overall size of an application or website.
Heavy Interfaces: UIs that use very high-resolution photos, background videos, complex animations, and custom fonts can be very large, sometimes taking up several gigabytes (GB) of storage. This is common in high-end video games.
Lightweight Interfaces: UIs that use simple graphics (or no graphics at all), standard system fonts, and efficient code can be tiny, taking up only a few megabytes (MB).
Why does this matter?
Device Limitations: Many users, especially those in developing countries or with older models, have devices with very limited storage. If an app is too big, they simply cannot install it.
Download Times: A larger app or website takes longer to download, especially on a slow mobile data connection. Users are impatient and may give up if it takes too long.
Performance: Loading large assets into memory can slow down the performance of the UI, making it feel laggy.
A smart designer must make a trade-off. They might want to use a beautiful, high-quality video on the homepage, but they must consider if the negative impact on storage, download speed, and performance is worth it.
For our Majestic Cinema project, we need to choose images that are good quality but also optimised (compressed) to keep the overall size of the interface low.
Last modified: September 19th, 2025
