Introduction to Event-Driven Programming

Active learning helps Year 3 pupils grasp event-driven programming because they experience firsthand how code pauses and reacts to real-time inputs. When students manipulate sprites through clicks or key presses, they build intuition for conditional logic and sequencing in a way that abstract explanations cannot match.

• Year 3
• Computing
• 4 activities
• 20 min–45 min

Learning Objectives

1. Construct a program where a sprite reacts to a mouse click using an event handler.
2. Explain how an 'if-then' statement allows a program to respond to a specific trigger.
3. Compare a script that runs once to a loop that waits for an event.
4. Identify the event that causes a sprite to perform an action in a given program.

Problem-Based Learning

⏱ 30 min·Pairs

Pairs Coding: Sprite Click Reaction

In pairs, students select a sprite and add an 'if mouse clicked then jump' block. They test by clicking different screen areas, then modify to include sound effects. Pairs swap computers to try each other's code and suggest one improvement.

Prepare & details

Explain how an 'if-then' statement helps a game respond to a player.

Facilitation Tip: During Pairs Coding, circulate to ensure partners alternate roles every two minutes to keep both engaged with the 'when clicked' and 'if-then' blocks.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 45 min·Small Groups

Small Groups: Event Chain Challenge

Groups build a sequence of three events: key press makes sprite spin, mouse click changes backdrop, loudness sensor triggers speech. They run the program as a team, timing responses, and present the most creative chain to the class.

Prepare & details

Compare a sequence that runs once to a loop that waits for an event.

Facilitation Tip: For the Event Chain Challenge, provide colored sticky notes so groups can map out events before coding, preventing tangled logic in their scripts.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 20 min·Whole Class

Whole Class: Broadcast Event Demo

Project a shared Scratch file. Class calls out events like 'green flag' or 'spacebar'; teacher adds broadcasts live. Students predict outcomes, then vote on code fixes for bugs, reinforcing event connections.

Prepare & details

Construct a simple program where a sprite reacts to a mouse click.

Facilitation Tip: In the Broadcast Event Demo, pause after each step to ask students to predict what will happen next, reinforcing the link between triggers and responses.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 25 min·Individual

Individual: Personal Event Story

Each pupil creates a sprite that reacts to two custom events, such as arrow keys for movement and click for dialogue. They add a short story backdrop and test independently before sharing screenshots.

Prepare & details

Explain how an 'if-then' statement helps a game respond to a player.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Teaching This Topic

Teach event-driven programming by starting with tangible examples students can manipulate directly, like clicking sprites to change colors. Avoid overwhelming them with abstract flowcharts—instead, use live coding where you model debugging when events don’t occur as expected. Research shows that young learners solidify concepts when they see immediate, visible consequences of their code, so prioritize projects where actions and reactions are clear and repeatable.

What to Expect

Successful learning looks like students confidently identifying triggers, writing conditional responses, and debugging mismatches between events and actions. By the end of the activities, pupils should explain why their sprite only moves when clicked, not automatically.

Watch Out for These Misconceptions

Common Misconception

During Pairs Coding: Sprite Click Reaction, students may assume the sprite moves automatically without a click.

What to Teach Instead

Ask pairs to deliberately remove the 'when this sprite clicked' block and observe what happens. Redirect them to re-insert the trigger to restore functionality, highlighting the necessity of event triggers.

Common Misconception

During Small Groups: Event Chain Challenge, students might think 'if-then' statements run every frame regardless of input.

What to Teach Instead

Challenge groups to test their code with no keyboard or mouse input. Have them present why the sprite did not move, guiding them to recognize that conditions require specific triggers to evaluate as true.

Common Misconception

During Whole Class: Broadcast Event Demo, students may believe events occur without player action.

What to Teach Instead

During the demo, deliberately do not press any keys or click the mouse. Ask students to predict whether the sprite will react, then discuss why the sprite only responds when the designated event occurs.

Assessment Ideas

Exit Ticket

After Pairs Coding: Sprite Click Reaction, provide students with a Scratch project where a sprite changes color when clicked. Ask them to write down: 1. What is the event in this program? 2. What action happens when the event occurs?

Discussion Prompt

After Small Groups: Event Chain Challenge, ask students: 'Imagine you are designing a game where a character needs to jump when the spacebar is pressed. How would you tell the computer to make the character jump only when the spacebar is pressed, and not all the time?'

Quick Check

During Whole Class: Broadcast Event Demo, show students two code snippets: one a simple sequence and one using a 'when this sprite clicked' block. Ask them to hold up one finger for the sequence and two fingers for the event-driven code, explaining their choice.

Extensions & Scaffolding

• Challenge early finishers to add a second event to their sprite, such as changing direction when the arrow keys are pressed.
• Scaffolding for struggling students: Provide pre-written code snippets for the 'when clicked' and 'if-then' blocks they need to assemble.
• Deeper exploration: Introduce a 'broadcast' block to coordinate actions between multiple sprites, showing how events can trigger chains of responses.

Key Vocabulary

event	A specific occurrence or trigger that a program can detect, such as a mouse click or a key press.
event handler	A block of code that waits for a specific event to happen and then runs a set of instructions in response.
if-then statement	A programming structure that checks if a condition is true; if it is, then a specific action is performed.
trigger	The specific event that causes a program to execute a particular command or set of commands.