AP CSP Day 18 - Traversing Lists

Course Information

• Course: AP Computer Science Principles
• Unit: Big Idea 1 - Creative Development (CRD)
• Lesson: Day 18 (50 minutes)
• Learning Objective: CRD-1.R - Traverse lists appropriately

Learning Objectives

Primary Goals

Students will be able to:

1. Understand the concept of traversing lists in programming
2. Create programs that traverse lists effectively
3. Test and refine program logic involving list traversal
4. Analyze real-world scenarios that require list traversal

AP Exam Alignment

• Big Idea 1: Creative Development (10-13% of AP Exam)
• Essential Knowledge: CRD-1.R.1, CRD-1.R.2, CRD-1.R.3
• Computational Thinking Practice: 1.A - Investigate the situation, context, or task

Lesson Structure (50 minutes)

Opening Hook (10 minutes)

1.1 Welcome & Lesson Preview (5 minutes)

Teacher Activities:

• Recap previous day's content on list operations and algorithms
• Introduce today's topic on traversing lists

Student Activities:

• Think about: "What are some examples where we use list traversal in daily life?"

1.2 List Traversal Examples Challenge (5 minutes)

Activity: "Identify the List Traversal"
Instructions:

• Groups of 4-6 students
• Identify list traversal in given scenarios
• Discuss the importance of list traversal

Purpose: Activate thinking about list traversal

Core Content Instruction (20 minutes)

2.1 What is List Traversal? (10 minutes)

Definition (CRD-1.R.1):

List traversal involves visiting each element of a list one by one.

Key Concepts:

• For loops: for item in my_list:
• Index-based traversal: for i in range(len(my_list)):
• Nested traversal: Traversing lists within lists

Case Study: Using list traversal in a simple program

• Program: Print all student names
• Traversal structure: for name in students: print(name)

2.2 Common List Traversal Techniques (5 minutes)

Examples:

• Simple traversal: for item in my_list:
• Index-based traversal: for i in range(len(my_list)):
• Nested traversal: for sublist in my_list: for item in sublist:

Discussion Questions:

1. What makes good list traversal?
2. Can you think of an example where list traversal is used in daily life?
3. Why is list traversal important in programming?

2.3 Advanced Traversal Concepts (5 minutes)

Why is it important?:

• Efficiency: Handling large datasets quickly
• Complexity: Solving more intricate problems

Discussion Questions:

1. How can we handle large datasets with advanced traversal techniques?
2. Why is complexity important when using list traversal?

Hands-On Activity (15 minutes)

3.1 Group Project: Create a Program with List Traversal (15 minutes)

Activity: "Design a Program"
Instructions:

• Groups of 3-4 students
• Design a program that uses list traversal effectively
• Test the program for correctness
• Present the program to the class

Materials:

• **Program design worksheet
• **List traversal checklist

Learning Goals:

• **Understand list traversal
• **Create programs using list traversal effectively
• **Test program logic involving list traversal
• **Present ideas effectively

Assessment:

• **Group participation
• **Program quality
• **Testing thoroughness
• **Presentation clarity

Closure & Preview (5 minutes)

4.1 Key Concepts Review (2 minutes)

Today's Learning Highlights:

1. ✅ Understanding the concept of traversing lists in programming
2. ✅ Creating programs that traverse lists effectively
3. ✅ Testing and refining program logic involving list traversal
4. ✅ Analyzing real-world scenarios that require list traversal

AP Exam Connection:

• These concepts will appear in AP exam multiple choice questions
• Understanding list traversal is crucial for the Create Performance Task

4.2 Next Class Preview (3 minutes)

Day 19 Topic: "2D Lists and Nested Loops"

• Learning Objective: CRD-1.S - Use 2D lists and nested loops appropriately
• Activity: Practicing 2D list operations
• Homework: Think about a recent program you used. What list traversal did it employ?