Computer Science
Grade 7
20 min
App Design Principles
App Design Principles
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1
Introduction & Learning Objectives
Learning Objectives
Identify the target audience for a given app idea.
Define User Interface (UI) and User Experience (UX).
Explain the importance of clarity and consistency in app design.
Apply the 'Keep It Simple' principle to a basic app layout.
Sketch a simple wireframe for an app screen that includes key features.
Identify common design mistakes in a sample app.
Ever used an app that was super confusing or hard to use? 🤔 Let's learn the secrets to designing apps that are awesome and easy for everyone!
In this lesson, you'll discover that building a great app is not just about coding; it's about smart design. We'll explore the basic principles that make apps like TikTok and YouTube so popular and simple to navigate, so you can plan your ow...
2
Key Concepts & Vocabulary
TermDefinitionExample
User Interface (UI)Everything you see and interact with on the screen, like buttons, icons, text, and images. It's the 'look' of the app.In a calculator app, the UI is the number pad, the display screen where the answer shows up, and the operation buttons (+, -, *, /).
User Experience (UX)How a person feels while using the app. Is it easy, fun, confusing, or frustrating? It's the 'feel' of the app.A good UX for a game app means the controls are easy to understand and the player doesn't get stuck on the menu screen.
Target AudienceThe specific group of people you are designing the app for. Their age, interests, and needs will guide your design choices.The target audience for a math game with cartoon characters is likely elementary sc...
3
Core Syntax & Patterns
K.I.S.S. (Keep It Simple, Student!)
Don't add unnecessary buttons, text, or images. Every element on the screen should have a clear purpose.
Use this principle to avoid overwhelming your user. A clean, simple screen is easier to understand and use than a cluttered one.
Clarity Over Clutter
Make sure icons and buttons are easy to understand. Use clear labels and avoid confusing symbols.
Your user should know exactly what will happen when they tap a button. A magnifying glass icon should mean 'Search', not 'Zoom In' unless it's a photo app.
The Three-Tap Rule
A user should be able to get to any key feature of your app in three taps or less.
This is a guideline to make your app efficient. If it takes ten taps to find the settings page, user...
4 more steps in this tutorial
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Challenging
A developer creates a new social media app for teenagers. The UI uses large, simple buttons and a very plain font, similar to an app for senior citizens. Even if the app works perfectly, why might the User Experience (UX) be poor for its target audience?
A.The app will be too slow because of the large buttons.
B.The design feels boring and not 'cool', so the target audience won't enjoy using it.
C.The Three-Tap Rule is automatically violated by using large buttons.
D.The app will be too clear and easy to understand.
Challenging
You are designing a 'School Lunch Menu' app. You want to follow the K.I.S.S. principle, but you also need to show the menu for every day of the week. Which design choice best balances these two goals?
A.Show today's menu in large text, with small, clear buttons for other days.
B.Display the entire month's menu on the first screen in a tiny font.
C.Create a separate app for each day of the week.
D.Only show today's menu and provide no way to see other days.
Challenging
A design plan for a photo-editing app's main screen includes: 25 filter buttons, sliders for brightness, contrast, and saturation, a 'share' button, a 'save' button, an 'undo' button, and a 'help' button, all visible at once. What is the MOST critical design flaw in this plan?
A.The target audience is not clear.
B.The design lacks feedback mechanisms.
C.The design is probably inconsistent with other screens.
D.It completely ignores 'Clarity Over Clutter' and the K.I.S.S. principle.
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