Watson Glaser Inference
How likely is it that this inference is true, based only on the facts you are given? Your ability to judge how far a conclusion is supported by given facts: to tell what is certain, what is likely, what cannot be told, and what is wrong.
Inference · Example
A public swimming pool reduced its opening hours from 7 am to 10 pm, to 8 am to 9 pm, last month. Since then, the number of visitors each week has fallen by 5%, while weekly income from entry fees has stayed the same. The manager has said that the pool is considering raising its entry fees.
Proposed statement
The pool is now open for fewer hours each day than before.
Practice tests
Every practice set has 10 questions. Pick one to start.
Every answer option, explained
What you'll actually see
A short statement of facts (a paragraph) that you must regard as true. 3 to 5 proposed inferences per statement of facts. The real test lists the same five answer options and tells you to use commonly accepted knowledge only where practically everyone shares it. Our practice items follow the same format, with 3 to 5 inferences per statement of facts.
True
The inference follows beyond reasonable doubt from the facts. You could prove it using only the statement (including restating a fact in other words or doing a simple calculation).
Facts: 'The firm has 200 staff and 40 of them work part-time.' Inference: 'Fewer than half of the staff work part-time.' True.
Probably True
The facts, together with commonly accepted knowledge, make the inference more likely to be true than false, but they do not settle it. A reasonable exception or alternative is possible.
Facts: 'Sales of umbrellas doubled in the week it rained every day.' Inference: 'The rain increased the demand for umbrellas.' Probably True.
Insufficient Data
The facts give no basis for judging the inference either way. You cannot tell whether it is more likely to be true or false.
Facts: 'The café opened in March.' Inference: 'The café makes a profit.' Insufficient Data.
Probably False
The facts, together with commonly accepted knowledge, make the inference more likely to be false than true, but they do not completely rule it out.
Facts: 'The shop sells only fresh fruit and vegetables.' Inference: 'The shop sells petrol.' Probably False (strictly it is not impossible, but it is very unlikely).
False
The inference is definitely wrong: it contradicts the facts or something that necessarily follows from them, or it misreads the facts.
Facts: 'All 30 pupils passed the exam.' Inference: 'Some pupils failed the exam.' False.
Worked example
A public swimming pool reduced its opening hours from 7 am to 10 pm, to 8 am to 9 pm, last month. Since then, the number of visitors each week has fallen by 5%, while weekly income from entry fees has stayed the same. The manager has said that the pool is considering raising its entry fees.
Statement 1
The pool is now open for fewer hours each day than before.
The old hours were 15 hours (7 am to 10 pm), the new hours are 13 hours (8 am to 9 pm). The calculation settles it: True.
True
Statement 2
The fall in visitor numbers was caused by the shorter opening hours.
The fall followed the change, and fewer opening hours normally mean fewer chances to visit. But the passage does not state the cause, and other things could have contributed, so it is Probably True, not True.
Probably True
Statement 3
Most of the pool's visitors are under 16 years old.
The passage gives numbers of visitors and income, but nothing about who the visitors are. There is no basis for a judgement either way: Insufficient Data.
Insufficient Data
Statement 4
The manager is sure that raising entry fees would not affect visitor numbers.
The manager is only 'considering' a rise, which suggests uncertainty about the effects. A manager who is certain would normally just decide. It is Probably False because the passage does not rule it out.
Probably False
Statement 5
The pool's weekly income from entry fees has fallen.
The passage says income 'has stayed the same'. A fall contradicts this: False.
False
Know what is being assessed
How Inference works
An inference is a conclusion that can be drawn from facts. If the lights are on in a house and you can hear voices, you might infer that somebody is at home. That inference may be right, but it may also be wrong: the people could have left with the lights and the television still on.
Each exercise starts with a statement of facts. Treat these facts as true. Below the statement you will find several proposed inferences, which are conclusions that some people might draw from the facts.
Judge every inference on its own. For each one, choose the answer that best describes how true or false the inference is, given the facts. More than one inference can have the same answer, and a statement of facts can lead to several True or several False answers.
Use only the facts in the statement, plus ordinary knowledge that practically everybody has. Do not use specialist knowledge or personal opinions.
In the full test you have about one minute per question. Most inference items take 30 to 60 seconds. If you are stuck between two neighbouring answers, decide which direction the facts point in, pick the answer, and move on.
Where candidates lose points
- Liking the sound of it. An inference can be sensible or plausible in real life but still not be supported by the passage.
- Correlation treated as cause. When one thing follows another, they may be linked, but the passage may not say that one caused the other. This is usually Probably True at most, or Insufficient Data if there is no real link.
- Extreme wording. 'Always', 'never', 'all', 'only' and 'every' are rarely supported by the facts. They often turn an acceptable inference into a False or Probably False one.
- Ignoring the group in the passage. A result for one group (adults, people in a survey, one company) does not automatically apply to another group.
- Defaulting to Insufficient Data. When the facts clearly point one way, 'I cannot be sure' is the wrong answer. Pick the probable answer.
- Confusing 'not found' with 'not there'. Not finding evidence of something makes it less likely, but does not prove that it does not exist.
A smarter approach
- 01
Read the statement of facts carefully, once, and note the key numbers, quantity words (some, most, all, few) and time words.
- 02
Read the inference slowly. Underline the single claim it makes. Watch for extra claims hidden in the wording (causes, reasons, comparisons, 'always', 'only').
- 03
Ask: is the claim stated, or can I work it out with certainty? If yes, answer True (or False if the facts rule it out).
- 04
If not certain, ask: do the facts, together with what practically everyone knows, point one way? If yes, choose Probably True or Probably False, depending on the direction.
- 05
If the facts really say nothing relevant, choose Insufficient Data.
- 06
Check yourself: could a reasonable person think of a realistic exception? If so, step down from True to Probably True (or from False to Probably False).
Tips for Inference
Think of the five answers as a scale from 'certainly yes' to 'certainly no', with Insufficient Data in the middle
Think of the five answers as a scale from 'certainly yes' to 'certainly no', with Insufficient Data in the middle. First decide the direction (yes, no, or no basis), then decide how strong it is.
Never answer from what you believe about the real world alone
Never answer from what you believe about the real world alone. The passage comes first. Common knowledge is only used to tip the balance between 'probably' answers and 'insufficient data'.
Insufficient Data is not a safe default
Insufficient Data is not a safe default. If the facts clearly point one way, the answer is Probably True or Probably False. Use Insufficient Data only when the passage truly has nothing to say.
True and False are for inferences you could defend in a debate with nothing but the passage
True and False are for inferences you could defend in a debate with nothing but the passage. When in doubt between True and Probably True, ask yourself whether a realistic exception exists.
Do the maths when numbers are given
Do the maths when numbers are given. Percentages, totals and comparisons often make an inference True or False with no guessing. Check the base: is the percentage of the whole group or of a part?
Watch small words: 'almost', 'at least', 'mainly', 'some', 'most', 'may'
Watch small words: 'almost', 'at least', 'mainly', 'some', 'most', 'may'. One word can change True into False.
Judge each inference independently
Judge each inference independently. Do not look for a pattern in your answers.
Draw it out
Draw it out. A quick sketch of groups, numbers or a timeline often makes the answer obvious (a tip from Pearson's own candidate feedback report).
Pace yourself
Pace yourself. Spend most of your time on the middle answers (Probably True / Insufficient Data / Probably False), where most errors are made.
Make the format familiar before test day.
Start with a free set, then build up to full-length mock tests.