Computer Science · Class 12

Active learning ideas

Function Parameters: Positional and Keyword

Active learning helps students grasp function parameters because misunderstandings often arise when they only listen to explanations. When students test arguments directly, they see errors immediately and correct them through experience. This topic requires hands-on experimentation to build confidence in how positional and keyword arguments work together.

• CBSE Learning Outcomes
• CBSE: Computational Thinking and Programming - Functions - Class 12

• 20–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Collaborative Problem-Solving
• 30 min · Pairs

Pair Programming: Argument Order Challenge

Pairs define a function with three positional parameters, like calculate_area(length, width, unit). They write calls using positional order, then swap to cause errors and fix with keywords. Discuss readability differences.

Compare the use of positional arguments versus keyword arguments in function calls.

Facilitation Tip

During Pair Programming, circulate and listen for students explaining argument order explicitly so they verbalise the sequence rules.

What to look for

Present students with the following Python function definition: `def configure_printer(model, ink_level, duplex=True): pass`. Ask them to write two different function calls: one using only positional arguments, and another using a mix of positional and keyword arguments. Then, ask them to predict the output if `ink_level` is not provided.

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

Activity 02

• Collaborative Problem-Solving
• 45 min · Small Groups

Small Groups: Student Grade Calculator Design

Groups create a function with positional args for marks and keyword args for name, subject, scale='percentage'. Test mixed calls, add defaults, and share outputs. Rotate roles for coding and testing.

Design a function that effectively utilizes both positional and keyword parameters.

Facilitation Tip

In Small Groups, provide a checklist of requirements so students focus on parameter design rather than formatting.

What to look for

Provide students with a Python function and three different function calls. Ask them to identify which calls are valid and which would raise an error, explaining why. For example: `def greet(name, message='Hello'): print(f'{message}, {name}!')` Calls: `greet('Alice')`, `greet(message='Hi', name='Bob')`, `greet('Charlie', 'Good morning')`.

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

Activity 03

• Collaborative Problem-Solving
• 25 min · Whole Class

Whole Class: Output Prediction Relay

Project function definitions with mixed parameters. Teams predict outputs for 10 calls on slates, relay answers. Reveal with live execution and vote on common errors.

Predict the output of function calls with mixed parameter types.

Facilitation Tip

For the Output Prediction Relay, give a 2-minute warning before discussion so students finalise predictions and justify choices.

What to look for

Pose this question to the class: 'When would you choose to use keyword arguments over positional arguments, even if the function is simple? Consider code readability and future modifications.' Facilitate a brief class discussion to gauge understanding.

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

Activity 04

• Collaborative Problem-Solving
• 20 min · Individual

Individual: Debug Worksheet

Provide buggy code snippets with incorrect positional/keyword mixes. Students identify errors, rewrite calls, and verify in Python. Collect for feedback.

Compare the use of positional arguments versus keyword arguments in function calls.

Facilitation Tip

While students work on the Debug Worksheet, ask guiding questions like 'Why does this call fail? What would fix it?' instead of giving answers.

What to look for

Present students with the following Python function definition: `def configure_printer(model, ink_level, duplex=True): pass`. Ask them to write two different function calls: one using only positional arguments, and another using a mix of positional and keyword arguments. Then, ask them to predict the output if `ink_level` is not provided.

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

A few notes on teaching this unit

Teachers should start with concrete examples before abstract explanations, as students often confuse argument order with parameter names. Use live coding to demonstrate errors when arguments are swapped, then fix them together. Avoid rushing to keyword arguments before students master positional rules, as mixing too early can overwhelm them. Research shows that students retain parameter concepts better when they debug their own mistakes in pairs or small groups.

By the end of these activities, students will confidently distinguish between positional and keyword arguments, predict call outcomes accurately, and design functions that blend both methods effectively. They will also debug mixed calls without hesitation and explain their reasoning clearly.

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Watch Out for These Misconceptions

• During Pair Programming: Argument Order Challenge, watch for students assuming any order works for positional arguments.

  Ask each pair to intentionally swap two positional arguments and run the function. The immediate TypeError will help them see that order matters strictly.

• During Small Groups: Student Grade Calculator Design, watch for students placing keyword arguments before positional ones in their function calls.

  Have groups share their function calls on the board and mark the positions of positional versus keyword arguments. Discuss why one style fails and the other succeeds.

• During Output Prediction Relay, watch for students believing keyword arguments override positional ones when names match.

  Use a function with duplicate parameter names in the relay questions. Students will see Python raises an error, reinforcing that names must be unique.

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Methods used in this brief

• Collaborative Problem-Solving