WACE Computer Science: programming, networks, databases and cybersecurity

What the WACE Computer Science exam looks like

This is a written paper, not a coding test. The design brief gives a booklet of stimulus material, and the questions ask you to read it: network diagrams, entity relationship diagrams, data dictionaries, trace tables, algorithms in pseudocode, or screen captures of a database or a program.

You may use up to three calculators that cannot store programs or text, and also a Mathomat, a Mathaid or a system flowchart template. Extended answers can ask you to analyse extended algorithms, relational databases and tables, or to propose a solution and justify it.

What Unit 3 and Unit 4 cover

• Unit 3, programming and networking: structured and object-oriented programming, algorithms and pseudocode, testing, the interactions between users, developers, the law, ethics and society, then network communications, components and performance.
• Unit 4, databases and cybersecurity: data modelling with entity relationship diagrams, data integrity, normalisation, creating and querying a database with SQL, network threats and the measures that defend against them, and ethical and legal obligations when data is collected and stored.

Our Databases course teaches keys, joins and SQL from scratch, and the IP Addressing course covers subnetting.

Worked examples

A subnet question

A school network uses 192.168.10.0/26. A /26 prefix leaves 32 − 26 = 6 host bits, so there are 2⁶ = 64 addresses in each subnet, and two of them (the network and broadcast addresses) cannot be assigned to devices. That leaves 62 usable host addresses. The next subnet starts at 192.168.10.64.

Count hosts on a different mask in the IP Addressing course, then press Mark:

Reading an SQL query

An exam may show a table of orders and ask what a query returns, or ask you to write one.

SELECT customer_id, SUM(total) AS spent
FROM orders
GROUP BY customer_id
HAVING SUM(total) > 100
ORDER BY spent DESC;

This lists each customer who has spent more than 100 in total, largest first. The aggregation (SUM) with GROUP BY is the part the Year 12 Grade A description names: complex queries across tables, with calculated fields and aggregation.

A trace table

total = 0
FOR i = 1 TO 5
    IF i MOD 2 = 0 THEN
        total = total + i
    ELSE
        total = total - 1
    ENDIF
ENDFOR
OUTPUT total

The program outputs 3. Showing the table, not only the answer, protects your marks if you slip on one row.

School assessment, grades and the ATAR

SCSA sets the school-based weightings for Year 12 Computer Science: project 40%, test 10%, practical test 10% and examination 40%. The practical test is where you write code or SQL under supervision, and the project is an open-ended piece in which you design and build a solution. Schools give A to E grades and a school mark out of 100. That mark is moderated against exam marks at the school, averaged with the exam mark, and used by TISC in the ATAR.

Dates

Use the daily paper as a trial

SCSA does not publish trial exams, so your school sets its own. The free daily paper on the Year 12 Software Engineering track is a short timed trial of 8 questions worth 25 to 35 marks, marked as you go. It is not a full WACE paper, and it is not designed around SCSA's source-booklet format.

• It matches: databases and SQL, object-oriented programming, networking, encryption, and searching and sorting.
• It does not match: regular expressions, floating-point numbers, finite state machines and the theory of computation are in its rotation but not named in the WACE content.
• Practise reading a stimulus before the question. In the exam the booklet is where the data lives.

Exam answers

Answers and a worked mark scheme come with each daily paper once it has been marked. They are Uni-Sine's own, not official SCSA answers or past paper solutions.

Common WACE Computer Science mistakes

• Writing a SQL query that returns the right rows but omits the GROUP BY column.
• Counting 2ⁿ as the usable hosts, forgetting the network and broadcast addresses.
• Describing a security threat without naming the measure that counters it.
• Answering an ethics question with opinion alone. Name the stakeholder and the obligation.

Read next

Australia · WACEWACE Physics: ATAR exam, Units 3 and 4, worked examplesWACE Physics for Year 12: the SCSA ATAR Physics exam sections, Units 3 and 4, school marks, 2026 and 2027 dates and a daily trial paper.