*** In 2026 this external will be an Online Examination held on FRIDAY 27th NOVEMBER - PM ***
This standard provides students with an opportunity to broaden their understanding of essential computer science topics relevant to modern society. This exam asks students to show their understanding of an important computer science idea from one of the following topics: computer security, encryption, error control complexity and tractability, artificial intelligence. Students need to understand the concept, explain how it works, how it’s used, what impacts it has, and what problems or challenges come with it.
Every year, TWO topics are named in the NZQA Assessment Specifications for Teachers and Students to focus on. In the exam students choose to answer questions for ONE topic only
In 2025 the TWO topics are: Computer Security or Encryption.
Candidates will be required to respond in short and / or extended answers (800–1500 words in total) to questions relating to their choice of ONE of the following computer science concepts:
computer security OR
encryption
For 2026, questions on impacts will focus on human factors and social impact.
For computer security, questions may cover any of the following:
Authentication, antivirus, malware, education
VLANs*
VPNs – uses and limitations
School security*
Passwords management.
For encryption, questions may cover any of the following:
Types of encryption (symmetric, asymmetric, hashing)
VPNs – use of encryption
WPA2 / WPA3-Personal and WPA2 / WPA3-Enterprise in Wi-Fi*
Device encryption such as BitLocker*
Passwords managers
Digital signatures.
* Topics will focus on use in schools.
Every year an assessment report is released to support teachers and students understand how the exam was marked. There can be some specific detail which is worth reading through to help support students understand the grade recieved.
We recommend reading through the whole report yourself. These are found under the different years below but here are some of the key points:
candidates' overall performance in response to the given questions was higher than in the previous few years.
While the use of generative AI, alongside other published materials and online resources, is encouraged during preparation, relying on it solely for rote learning may diminish learners' authentic voices and lead to marginal assessment responses.
Candidates were asked to explain selected computer science topics by considering underlying algorithms, practical applications, and social impacts.
In 2024, Candidates had a choice of answering questions on artificial intelligence (AI), computer security, or error control. There was an even spread amongst the topics chosen to answer. Candidates did equally well on all topics.
Using subject-specific language successfully is important. This was particularly apparent in the artificial intelligence question about chatbots, where terms such as ‘natural language processing’ were used.
Candidates who attempted all questions were advantaged.
In the drop downs below you will find the Assessment Report, the Assessment Schedule and any exemplars NZQA provided
Note: Perviously to this year the 91898 external was a DCAT.
Topics: Artificial Intelligence (AI) or Encryption
2025 91898 Assessment Report
2025 91898 Assessment Schedule
2025 91898 Excellence Exemplar
2025 91898 Merit Exemplar
2025 91898 Achieved Exemplar
2024 91898 Assessment Schedule
2024 91898 Excellence Exemplar
* this was sat as a DCAT at the end of term 3.
2023 91898 Assessment Schedule
2023 91898 Excellence Exemplar
* This was a DCAT sat T3 week 10 or T4 week 1. There were 2 exams based on which week you were sitting it.
(you will complete this during your timetabled class)
Only work directly keyed by the candidate into their computer or device during the assessment session will be used in the assessment response. You will not use hard copy, online course resources, or notes of any type, to complete this assessment. You will not access internet resources.
You should aim to write between 800 and 1500 words in total, in about 1.5hrs.
By saving an assessment response at the end of the assessment session, the candidate verifies the work is their own. NZQA may digitally sample the candidate’s work to test its authenticity.
*** We will run a derived grade to help prepare you during class ***