Case study / HL extension (if applicable) - Computer Science IB Study Notes

The Case Study is a unique assessment component in IB Computer Science, examining students' ability to analyze a real-world scenario using computational thinking. For Higher Level (HL) students, this includes additional complex systems analysis and advanced programming concepts.

Key Definitions:

Case Study: A detailed examination of a real-world computing problem released annually by the IB, typically 4-6 months before examinations. Students must analyze stakeholders, system requirements, and computational solutions.

HL Extension Topics: Advanced content including object-oriented programming (OOP), recursion, linked lists, binary trees, and complex algorithm analysis that HL students must master beyond Standard Level requirements.

Stakeholder Analysis: The systematic identification and evaluation of individuals or groups affected by the computing system, including their needs, concerns, and influence on system design.

System Requirements: Functional and non-functional specifications that define what a system must do (functionality) and how it should perform (reliability, usability, security).

Computational Solution: An algorithmic approach combining data structures, control structures, and logical reasoning to solve problems within the case study context.

Cambridge Command Words for Case Study:

• Analyze: Break down the scenario into components and examine relationships
• Evaluate: Assess the effectiveness of solutions with justified conclusions
• Discuss: Present balanced arguments considering multiple perspectives
• Suggest: Propose solutions with reasoned justification based on the context

HL students must demonstrate deeper technical knowledge, including UML diagrams, complex data structure implementation, and sophisticated algorithm design beyond SL requirements.

The case study bridges theoretical computer science with practical application. Think of it as architectural planning for a building: you need blueprints (system design), materials (data structures), construction methods (algorithms), and consideration for occupants (stakeholders).

Real-World Application Example:

Consider a hospital patient management system (typical case study scenario):

Stakeholders include: patients seeking efficient care, doctors requiring quick access to records, administrators managing resources, IT staff maintaining security, and regulatory bodies ensuring compliance.

SL vs HL Distinction: SL students might propose a simple array-based appointment system, while HL students must design sophisticated solutions using linked lists for dynamic appointment scheduling, binary search trees for optimized patient record retrieval, or inheritance hierarchies representing different medical staff types.

Data Structure Selection Analogy: Choosing between arrays and linked lists is like deciding between a fixed apartment building (array - fast access, fixed size) versus a modular construction (linked list - flexible, dynamic growth).

HL-Specific Example - Recursion: Calculating medication dosage adjustments over time uses recursive functions, where each calculation depends on the previous state—like a Russian nesting doll, each level contains information needed for the next.

System Requirements Translation: When the case study states "the system must process 1000 transactions per second," this becomes a non-functional requirement affecting your algorithm choice—you'd select O(log n) binary search over O(n) linear search.

Memory Aid (SHED): Stakeholders, Hardware constraints, Efficiency requirements, Data structures guide your analysis approach.