OC test vs Selective test: what is the difference?
Both tests are run by the NSW Department of Education, both are done on a computer at a test centre, and both have a Thinking Skills section. That is why many parents mix them up. This page puts them side by side so you can plan which one your child sits, and when.
The short answer
- The OC test is sat in Year 4. It is for a place in an Opportunity Class in Year 5 and Year 6, inside a public primary school.
- The Selective test is sat in Year 6. It is for a Year 7 place in a selective high school (fully selective, partially selective or agricultural).
- They are separate applications. An OC place does not give your child a selective high school place, and a child who did not sit the OC test can still sit the Selective test.
Side by side
Question numbers and timing below come from recent years. The Department can change the format, so check its website before the test.
| OC placement test | Selective placement test | |
|---|---|---|
| Who sits it | Year 4 students | Year 6 students |
| What it is for | Year 5 and 6 Opportunity Class | Year 7 place in a selective high school |
| Reading | 14 questions, 40 minutes | 30 questions, 40 minutes |
| Mathematical Reasoning | 35 questions, 40 minutes | 35 questions, 40 minutes |
| Thinking Skills | 30 questions, 30 minutes | 40 questions, 40 minutes |
| Writing | No writing section | 1 task, 30 minutes |
| Usual timing | Apply November to February, test in early May | Apply November to February, test in early May |
The biggest practical difference for families is the Writing section: the OC test has none, the Selective test has one. The second is the size of the Thinking Skills section: 40 questions instead of 30, still at about one minute per question.
How Thinking Skills changes from OC to Selective
The question types are the same family: critical thinking (judging arguments), logic (ordering, matching, if-then rules) and problem solving (patterns, time, counting). What changes is the number of steps.
- OC level: usually two or three clues, a short argument, and one clear trap to avoid.
- Selective level: four or five conditions at once, longer arguments with a hidden assumption, and maths-style problems that need a plan before any sums.
- Speed: both give about one minute per question, so a child who still reads every option slowly at OC level will feel the pressure even more in Year 6.
You can read the full list of types with examples in our guide to Thinking Skills question types and our page on critical thinking questions.
Try one question at each level
These are written by us for practice and are not from any real test or from our free checks, so your child can still do those fresh. Give about one minute each.
Ari, Bec and Cal each have one pet: a cat, a dog or a goldfish.
• Ari's pet does not have fur.
• Bec does not own the dog.
Who owns the dog?
- Ari
- Bec
- Cal
- It cannot be worked out
Show the answer
A shop sells pens in packs of 3 and packs of 5. Mai bought 9 packs and got 37 pens altogether.
How many packs of 5 did she buy?
- 3
- 4
- 5
- 6
Show the answer
Notice the difference: the OC question needs two clues and a little elimination. The Selective question has no clue that points straight at the answer, so your child has to choose a method first (here, "pretend every pack is a small pack and count the extra").
Should my child sit both?
Many families do. Sitting the OC test in Year 4 is good experience of a timed, computer-based test, and the Thinking Skills habits carry straight over to Year 6. Some points to weigh up:
- Travel. An Opportunity Class may be in a different primary school from your child's current one. Think about the trip for Year 5 and 6, not only the result.
- Friends and wellbeing. Moving schools in Year 5 suits some children and not others. Ask your child how they feel.
- Not placed in OC? It does not decide the Selective outcome. Two more years of reading, maths and steady thinking practice make a real difference.
- Placed in OC? The child still applies and sits the Selective test like everyone else.
How to prepare for each
| Skill | For the OC test (Year 3 to 4) | For the Selective test (Year 5 to 6) |
|---|---|---|
| Thinking Skills | Learn each type one at a time, then short timed sets of 10 | Full 40-question sets in 40 minutes, review every mistake |
| Reading | Read daily and talk about why characters act as they do | Add poetry and comparing two short texts |
| Maths | Word problems, time, money, patterns | Multi-step problems, fractions, ratios and rates |
| Writing | Not tested, but keep a reading journal | One piece a week to a 30-minute timer |
For a month-by-month timeline, see our 6-month OC preparation plan or the Selective test 2027 guide. To see where your child stands right now, try the free OC practice test (Year 3 and 4) or the free Selective practice test (Year 5 and 6).
Always check the current details on the NSW Department of Education website: the placement test page and the key dates.
See where your child is today
20 questions with a 20-minute timer, an instant score for each skill and worked answers in English, Vietnamese, Chinese, Korean and Thai.
Free OC check (Year 3 and 4)Or the free Selective check (Year 5 and 6)
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