Assessment objective

SL

Index	Objective	Paper 1	Paper 2	IA	Sum
1	Demonstration of knowledge and understanding	24	13	9	46
2	Application	13	7	8	28
3	Construction, analysis, evaluation, and formulation	8	5	4	17
4	Skills usage	n/a	n/a	9	9
n/a	Weighting	$0.45$	$0.25$	$0.3$	1

| 4 | Skills usage | n/a | n/a | 9 | 9 | | n/a | Weighting | $0.45$ | $0.25$ | $0.3$ | 1 |

Paper 1 — Written Response

Paper 1 is a 2-hour examination (SL) or 2 hours 15 minutes (HL) that tests knowledge and understanding of the core syllabus.

Structure

Component	SL	HL
Section A	Short-answer questions	Short-answer questions
Section B	Extended-response questions	Extended-response questions
Section C (HL only)	n/a	Extended-response on HL topics
Total marks	80	100

What examiners look for

• Definitions: Always use the exact IB terminology. For example, define "abstraction" as "hiding unnecessary details to reduce complexity," not just "simplifying things."
• Command terms: Pay close attention to the verb at the start of each question. "Describe" requires detail; "Explain" requires a reason; "Compare" requires similarities AND differences; "Evaluate" requires a judgment with supporting evidence.
• Extended responses: Use PEEL (Point, Evidence, Explanation, Link) paragraphs. Aim for 3–4 well-developed points per essay question.

Common pitfalls

• Writing everything you know about a topic instead of answering the specific question asked.
• Confusing SL and HL content — only use HL material in Paper 1 if you are an HL student and the question targets HL objectives.
• Leaving diagrams unlabeled. Every diagram must have a title and clear labels.

Exam tips

• Spend roughly 1 minute per mark. For a 6-mark extended response, aim for about 6 minutes of writing.
• Read all questions before starting. Answer the questions you are most confident about first to secure easy marks.
• Use the mark allocation as a guide for depth. A 2-mark question needs a brief answer; a 10-mark question needs a structured essay with examples.

Paper 2 — Problem Solving

Paper 2 is a 1-hour examination (SL) or 1 hour 45 minutes (HL) focused on applying computational thinking to unseen problems.

Structure

Component	SL	HL
Section A	Scenario-based short answer	Scenario-based short answer
Section B (HL only)	n/a	HL-only scenario question
Total marks	45	70

Key skills tested

• Tracing algorithms: You may be given pseudocode or Python code and asked to determine the output for a given input.
• Writing algorithms: Given a problem description, you must produce a solution in pseudocode or Python.
• Data structures: Be prepared to manipulate arrays, linked lists, stacks, queues, trees, and hash tables (HL).
• Computational thinking: Decomposition, pattern recognition, abstraction, and algorithm design.

Worked example: Tracing an algorithm

Consider the following Python code:

def mystery(data):
    result = 0
    for i in range(len(data)):
        if data[i] > data[i - 1]:
            result += data[i]
    return result

print(mystery([3, 7, 2, 9, 5]))

Trace table:

i	data[i]	data[i-1]	Condition	result
0	3	5	False	0
1	7	3	True	7
2	2	7	False	7
3	9	2	True	16
4	5	9	False	16

Output: 16

Exam tip: When i = 0, data[i - 1] accesses the last element (index -1 in Python). Watch for this wrap-around behavior in exam questions.

Worked example: Writing an algorithm

Question: Write an algorithm that takes a list of integers and returns the two largest distinct values.

def two_largest(data):
    if len(data) < 2:
        return None
    largest = max(data[0], data[1])
    second = min(data[0], data[1])
    for value in data[2:]:
        if value > largest:
            second = largest
            largest = value
        elif value > second and value != largest:
            second = value
    return largest, second

Exam tip: Always consider edge cases — empty lists, single-element lists, lists with all identical values. State your assumptions clearly.

Internal Assessment (IA)

The IA accounts for 30% of the total grade and consists of a computational solution to a client-identified problem.

Requirements

Criterion	Description	Maximum marks
A	Planning	6
B	Solution Overview	6
C	Development	12
D	Functionality and extensibility of solution	4
E	Evaluation	6
F	Abstract	2
	Total	36

Planning (Criterion A)

• Identify a clearly defined client and a genuine problem they face.
• The problem must have a computational solution — avoid trivial projects.
• Define the success criteria (at least 3 measurable criteria the solution must meet).
• Justify why the chosen techniques (e.g., programming language, data structures) are appropriate.

Development (Criterion C)

• Use appropriate data structures and explain why you chose them.
• Include evidence of iterative development (screenshots of versions, test logs).
• Write well-structured, documented code with meaningful variable names.
• Handle errors and invalid input gracefully.

Evaluation (Criterion E)

• Test against your success criteria from Criterion A.
• Include user feedback from your client.
• Discuss limitations of your solution and suggest improvements.
• Be honest — examiners value genuine self-reflection over hollow praise.

Common IA mistakes

• Choosing a project that is too simple (e.g., a basic calculator) or too complex (e.g., a full social network).
• Failing to include meaningful client interaction throughout the process.
• Not testing edge cases or not documenting test results.
• Writing code comments that merely restate the code rather than explaining the purpose.

Command Terms Reference

Understanding command terms is critical for Paper 1 and Paper 2:

Command Term	What it means
Define	Give the precise meaning of a term
Describe	Give a detailed account
Explain	Give a detailed account including reasons or causes
Discuss	Offer a considered and balanced review that includes a range of arguments
Evaluate	Make an appraisal by weighing up the strengths and limitations
Compare	Give an account of the similarities and differences between two or more items
Justify	Give valid reasons or evidence to support an answer or conclusion
Outline	Give a brief account or summary
Analyse	Break down in order to bring out the essential elements or structure
To what extent	Consider the merits or otherwise of an argument or concept

Exam tip: Underline or circle the command term in the exam question before you begin writing. This ensures you address the question at the correct cognitive level.

Grade Boundaries

Grade boundaries vary each examination session. As a general guide for a recent session:

Grade	SL (approx.)	HL (approx.)
7	75–100%	73–100%
6	64–74%	62–72%
5	52–63%	50–61%
4	40–51%	38–49%
3	27–39%	25–37%

Note: These are approximate boundaries and shift each year. Always check the most recent IB subject report for your session.

Time Management Strategy

A recommended approach for the final revision period:

1. Weeks 1–2: Review all core topics. Create summary sheets for each topic area.
2. Weeks 3–4: Practice past papers under timed conditions. Focus on understanding mark schemes.
3. Weeks 5–6: Target weak areas identified from practice papers. Revise IA notes and ensure all criteria are fully addressed.
4. Final week: Light review of command terms and key definitions. Practice one full Paper 1 and one Paper 2 under exam conditions.

Topic Weighting Guide

Understanding which topics carry the most marks helps you prioritize your revision.

SL Core Topics

Topic	Approximate Paper 1 Weight	Paper 2 Relevance
System Fundamentals	High	Scenario-based
Computer Organization	Medium	Trace questions
Networks	Medium	Scenario-based
Computational Thinking	Very High	Algorithm design

HL Additional Topics

Topic	Approximate Paper 1 Weight	Paper 2 Relevance
Abstract Data Structures	High	Algorithm tracing
Resource Management	Medium	Scenario-based
Control	Medium	Scenario-based

Options

Option	Paper 1 Weight	Paper 2 Relevance
Databases	Medium	SQL queries
Modelling and Simulation	Medium	Scenario-based
Web Science	Medium	Scenario-based
Object-Oriented Programming	Medium	Code tracing

Exam tip: Computational Thinking consistently carries the highest mark allocation. Ensure you are comfortable with algorithm design, tracing, and Big-O notation before focusing on other areas.

Worked Example: Answering a 10-Mark Question

Question: "Evaluate the impact of cloud computing on data storage and processing in modern organizations."

Sample answer structure (using PEEL):

Point: Cloud computing has significantly reduced the cost of data storage for organizations.

Evidence: Instead of purchasing and maintaining expensive on-premises servers, organizations can rent storage space from providers such as AWS, Google Cloud, or Microsoft Azure on a pay-as-you-go basis. Small businesses that previously could not afford enterprise-grade infrastructure can now access the same capabilities.

Explanation: This cost reduction is achieved through economies of scale — cloud providers serve millions of customers and can spread infrastructure costs across them. Additionally, the cloud model converts capital expenditure (buying hardware) into operational expenditure (monthly subscription), improving cash flow.

Link: This demonstrates that cloud computing has democratized access to powerful computing resources, though it also introduces dependencies on third-party providers and potential security concerns.

Point: However, cloud computing raises significant data privacy and security concerns.

Evidence: When data is stored on third-party servers, organizations must trust the provider's security measures. High-profile breaches (e.g., the Capital One data breach in 2019, which exposed 100 million customer records) illustrate the risks. Additionally, data sovereignty laws (such as GDPR in the EU) restrict where data can be stored and processed.

Explanation: Organizations must carefully evaluate their cloud provider's compliance with relevant regulations and implement additional security measures (encryption, access controls). The shared responsibility model means that while the provider secures the infrastructure, the customer is responsible for securing their data.

Link: Therefore, while cloud computing offers clear advantages in cost and scalability, organizations must balance these benefits against the risks of data breaches and regulatory non-compliance.

Exam tip: For a 10-mark question, aim for 4–5 well-developed points. Each point should include specific evidence and explanation. The conclusion should synthesize your arguments rather than simply restating them.

Common Mistakes by Criterion

Paper 1 — Knowledge and Understanding

• Vague definitions that lack precision (e.g., defining "algorithm" as "a way to solve a problem" without mentioning finiteness or step-by-step nature).
• Confusing related concepts (e.g., confusing "abstraction" with "encapsulation" or "compilation" with "interpretation").
• Failing to use examples to illustrate definitions.

Paper 2 — Application and Problem Solving

• Not reading the scenario carefully and missing key details.
• Writing code that is syntactically correct but logically flawed.
• Not testing algorithms with appropriate test data.
• Missing edge cases in algorithm design.

IA — Internal Assessment

• Choosing a project that lacks a genuine client need.
• Writing a solution overview that is too vague (Criterion B).
• Not including enough evidence of iterative development (Criterion C).
• Providing a superficial evaluation that does not genuinely assess the solution against success criteria (Criterion E).

Revision Checklist

Use this checklist to track your preparation:

• I can define all key terms from the syllabus
• I can explain the machine instruction cycle (fetch-decode-execute)
• I can trace algorithms using trace tables
• I can write algorithms in pseudocode and Python
• I can implement and explain common data structures (arrays, stacks, queues)
• I can compare sorting and searching algorithms by efficiency
• I understand network topologies, protocols, and security
• I can discuss ethical issues related to computing (privacy, AI bias, digital divide)
• I have completed at least 5 past papers for each paper under timed conditions
• I have reviewed my IA against all criteria and made improvements
• I know the command terms and can identify them in exam questions