Selective thinking: strengthen an argument (8 questions)

Quick Answer

A statement strengthens an argument only if it makes the conclusion more likely to be true. A statement that merely agrees with the conclusion, or that is about something else, does not. This page from Braintree Coaching Australia has eight original questions for Year 5–6 children, one worked model and a strengthens, neutral or weakens label for every option. It is free, needs no sign-up, and takes about 25 minutes including review.

What does it mean to strengthen an argument?

An argument has a conclusion (what someone wants you to believe) and a reason. To strengthen it, add something that makes the link between the reason and the conclusion tighter. To weaken it, add something that makes the link looser, such as a different explanation.

Every option below is one of three kinds:

• Strengthens: it makes the conclusion more likely.
• Neutral: it has no effect, either because it is unrelated or because it only says the conclusion is popular.
• Weakens: it makes the conclusion less likely.

This is skill practice, not a copy of official test items. The NSW Department of Education publishes the real format on its Selective high school practice tests page, which describes Thinking Skills as 40 questions in 40 minutes. It does not publish a list of question types, so we do not claim that strengthen-an-argument items appear on the test. They are one of the ways we practise careful reasoning. For the wider guide, see selective thinking skills.

Worked model

Question M. Argument: "The school should plant a vegetable garden, because it will help children eat more vegetables." Which one statement would most strengthen this argument?

• A. The garden would be next to the oval.
• B. Many children say a garden is a good idea.
• C. At another school, after a garden was planted, the vegetables children ate at lunch rose over a term.
• D. At another school, children ate no more vegetables after planting a garden.

Working:

1. The conclusion is that a garden will help children eat more vegetables.
2. Option B agrees with the plan. Children liking the idea is not evidence about what they eat. It is neutral.
3. Option A is about the location. It is neutral.
4. Option D is a case where the plan did not work. It weakens.
5. Option C is a case where a garden was followed by more vegetables eaten. It strengthens. The answer is C.

Option	Label	Why
A	neutral	Where the garden sits is not linked to what children eat.
B	neutral	This agrees with the plan but is not evidence that children would eat more vegetables.
C	strengthens	A similar case where a garden was followed by more vegetables eaten.
D	weakens	A similar case where the plan did not lead to the result.

The eight questions

Work on paper. Read the argument, say its conclusion in your own words, then label each option as strengthens, neutral or weakens before you choose. Exactly one option strengthens in each question.

Question 1. Argument: "The council should keep the Eastwood library open until 8 pm on weeknights, because more teenagers would use it to study." Which one statement would most strengthen this argument?

• A. Most teenagers in the area have sport training or a part-time job until 8 pm or later on weeknights.
• B. The library building was opened in 1998.
• C. When a nearby library began opening until 8 pm, visits by 13 to 17 year olds after 5 pm rose each month for a year.
• D. Many residents say longer opening hours would be a good idea.

Question 2. Argument: "Hartley Primary should hold its sports carnival in the morning, because students run faster in the morning." Which one statement would most strengthen this argument?

• A. Many students say they would rather have the carnival in the morning.
• B. The carnival has been held on the second Friday of term for ten years.
• C. In a trial last year, the same students' 100 m times were faster at 10 am than at 2 pm.
• D. The school track is wet most mornings, and students run more slowly on a wet track.

Question 3. Argument: "Dan's bakery sells more bread on Saturdays because it puts a sign on the footpath." Which one statement would most strengthen this argument?

• A. On the Saturdays the sign stayed inside because of rain, the bakery sold fewer loaves than on Saturdays when it was out.
• B. The sign is painted blue and white.
• C. The bakery sells the most bread on market Saturdays, whether or not the sign is out.
• D. Dan thinks the sign is a very good idea.

Question 4. Argument: "The plants in the school garden grew taller because the class used the new fertiliser." Which one statement would most strengthen this argument?

• A. The fertiliser comes in a green bag.
• B. Several students think fertiliser helps plants to grow.
• C. A second bed with the same sun and water but no fertiliser grew less.
• D. The fertilised plants were all in the sunniest bed. The others were in the shade.

Question 5. Argument: "Reading for 20 minutes each night improves a student's spelling test results." Which one statement would most strengthen this argument?

• A. Spelling tests are held every Friday.
• B. Among 120 students with similar starting scores, those who read for 20 minutes each night for a term improved more than those who did not.
• C. The students who read each night were also the ones who had a weekly spelling tutor.
• D. Teachers say reading is a lovely habit for children.

Question 6. Argument: "The town should close Park Street to cars before and after school, because it would be safer for children walking to school." Which one statement would most strengthen this argument?

• A. In another town, near-misses involving children fell in the term after a similar street was closed at school times.
• B. Park Street is 600 metres long.
• C. A petition to close the street has 300 signatures.
• D. Cars would be sent down Elm Lane, where most children cross to reach school and no one supervises the crossing.

Question 7. Argument: "Taking a 5-minute break every 20 minutes cuts careless errors in Mia's maths homework." Which one statement would most strengthen this argument?

• A. Mia's friends also like taking breaks.
• B. Mia's desk is next to the window.
• C. In the two weeks Mia took breaks, her homework sets were shorter and easier than in the two weeks before.
• D. On sets of the same difficulty at the same time of day, Mia made fewer careless errors with breaks than when she worked straight through.

Question 8. Argument: "Moving the fruit to eye level in the school canteen made more students choose fruit." Which one statement would most strengthen this argument?

• A. The canteen is open from 8:30 am to 1:30 pm.
• B. The canteen manager is pleased with the new layout.
• C. In the same week the canteen halved the price of fruit.
• D. After the move, fruit sales rose at this school and stayed the same at a school that did not change its display.

Answers and labels for every option

Check one question at a time. Each table labels all four options, so you can see why a wrong choice was tempting.

Question 1 answer: C

Option	Label	Why
A	weakens	If teenagers are busy until 8 pm, later hours do not give them a time to come.
B	neutral	The age of the building says nothing about who would use later hours.
C	strengthens	A like-for-like case where later hours were followed by more teenage visits.
D	neutral	This agrees with the plan but gives no evidence that teenagers would study there.

Question 2 answer: C

Option	Label	Why
A	neutral	A preference does not show anyone runs faster.
B	neutral	Past timing says nothing about speed.
C	strengthens	The same runners, two times of day, a direct measure of speed.
D	weakens	If the morning track is wet, morning running is likely to be slower, not faster.

Question 3 answer: A

Option	Label	Why
A	strengthens	Same day, sign in or out, sales differ: evidence the sign matters.
B	neutral	The colour of the sign is not evidence it brings customers.
C	weakens	This gives a different reason for the Saturday sales.
D	neutral	The owner's opinion repeats the claim; it is not evidence.

Question 4 answer: C

Option	Label	Why
A	neutral	The bag colour is unrelated to growth.
B	neutral	Opinion about fertiliser in general is not a result from this garden.
C	strengthens	The only difference is the fertiliser, so it supports the claim.
D	weakens	Sunlight could explain the height, so the fertiliser is less likely to be the cause.

Question 5 answer: B

Option	Label	Why
A	neutral	This is about when the tests happen, not what improves the results.
B	strengthens	A comparison between similar groups, with reading as the difference.
C	weakens	The tutor could explain the improvement instead of the reading.
D	neutral	This praises reading but says nothing about spelling results.

Question 6 answer: A

Option	Label	Why
A	strengthens	A similar case where the closure was followed by fewer near-misses.
B	neutral	Its length does not show whether the closure is safer.
C	neutral	Signatures show support, not that children would be safer.
D	weakens	The closure may move the danger to where the children are.

Question 7 answer: D

Option	Label	Why
A	neutral	Friends' preferences are not a result about Mia's errors.
B	neutral	The desk position is not linked to errors.
C	weakens	Easier sets could explain fewer errors without any help from the breaks.
D	strengthens	A fair comparison: only the breaks changed.

Question 8 answer: D

Option	Label	Why
A	neutral	Opening hours are not linked to what students choose.
B	neutral	A manager's pleasure is not a measure of what students chose.
C	weakens	The price drop is another reason more students might have chosen fruit.
D	strengthens	A comparison school that changed nothing shows no rise, so the move is the likely cause.

What mistakes should we look for?

Tally the kind of error. Each one needs a different fix.

Pattern	Seen in	What to practise next
Chose a statement that only agrees with the plan (opinion, popularity, signatures)	Questions 1, 2, 3, 4, 5, 6, 7, 8	Ask "does this tell me whether the conclusion is true, or only that people like it?"
Chose a statement that sounds related but is unrelated detail	Questions 1, 2, 3, 4, 5, 6, 7, 8	Say what the conclusion is about before reading the options
Chose a weakener because it was about the same topic	Questions 1, 2, 3, 4, 5, 6, 7, 8	Label each option before choosing

Can my child do one without options?

Argument: "Our class should swap desks every week, because children will make more friends." Ask your child to say one statement that would strengthen it and one that would weaken it.

Self-check: a strengthener gives a result linking the swap to friendships, such as another class making more friends after swapping. A weakener gives another explanation or a backfire, such as a class where swapping caused more arguments. "Most children think it is fun" is neutral.

What should we do after this set?

• If agreement-only options kept getting chosen, redo the questions and label every option out loud first.
• Stop at eight. Do not repeat the same questions the same day.
• For more mixed practice with worked solutions, open the NSW Selective practice resources.
• For the wider Thinking Skills guide, read selective thinking skills.
• The free mock tests need a free classroom account. Create one only when your child is ready for a timed sitting.

Sources and review

Official source: NSW Department of Education, Selective high school practice tests, for the Thinking Skills format (40 questions, 40 minutes). This page makes no claim about which question types appear on the test.

Where the questions came from: all eight questions and the model are original Braintree Coaching Australia material written for this page. None is taken from an official or third-party paper.

Author: James Rush, content writer, Braintree Coaching Australia.

Answer check: draft. A second solver (an AI model, not a teacher) matched every answer on 2026-10-15. A named teacher review has not yet been recorded for this set. If you find an error, please tell us.

Last updated: 2026-10-15.