A deductive reasoning test checks whether you can take a set of statements and work out exactly what must follow from them, no more and no less. This guide talks through typical deductive reasoning questions with generic worked examples, explains why capable people still slip up, and sets out how a deductive skills test fits into fair selection.

What a deductive reasoning test asks you to do

Deduction runs from the general to the specific. You are given premises, which you must accept as true for the purpose of the question, and you decide what conclusion they guarantee. The key word is guarantee. A conclusion that is likely, sensible or true in real life is not enough; it must follow necessarily from the information given.

The Viewpoint deductive reasoning test measures this skill: drawing logical conclusions from statements. It is relevant wherever people must apply rules, policies, contracts or specifications precisely.

Many deductive tests across the industry use one of two response formats. Some offer several conclusions and ask which one follows. Others present a single conclusion and ask you to judge it True, False or Cannot tell, where Cannot tell means the statements do not give enough information to decide either way.

Deductive reasoning questions: three worked illustrations

The examples below are generic illustrations written for this article. They are not taken from any Viewpoint test.

Illustration 1: the category argument. Suppose you are told that every van at a depot is serviced on a Monday, and that a particular van is at the depot. It follows that this van is serviced on a Monday. Now reverse it: you are told a van is serviced on a Monday. Does it follow that the van is at the depot? No. Other vans elsewhere might also be serviced on Mondays. The honest answer is Cannot tell.

Illustration 2: the conditional rule. A site rule says that if a visitor enters the workshop, they must wear goggles. You see someone wearing goggles. Did they enter the workshop? You cannot tell; people can wear goggles for other reasons. You see someone without goggles. If the rule was followed, that person did not enter the workshop. Many people find this second inference harder, even though it is the one the rule supports.

Illustration 3: the ordering problem. Four meetings must be scheduled. You are told the budget review is before the team briefing, the briefing is before the client call, and the client call is not last. From these statements alone you can work out that the budget review comes before the client call, and that some fourth meeting must be last.

Why capable people get deductive questions wrong

Deductive errors are rarely about intelligence alone. Johnson-Laird's mental model theory proposes that we reason by imagining the situations that the premises allow. Mistakes happen when we build one convenient picture and stop, missing an alternative possibility that would serve as a counterexample [1]. In Illustration 1, the reversed question tempts people because they imagine only the depot.

The conditional rule in Illustration 2 echoes Wason's famous selection task, in which participants check a rule by choosing cards to turn over. Very few chose the logically correct cards; most looked for cases that confirmed the rule rather than ones that could break it [2].

Stanovich and West's work on individual differences in reasoning adds an important caution. Gaps between people's answers and the logically correct answer can come from momentary performance errors, limits on working memory, or people interpreting the task differently from the way the test designer intended [3]. That is why clear instructions and practice questions matter so much for fair testing.

For candidates, the lesson is to treat the statements as the whole world of the question, look for a counterexample before accepting a conclusion, and sketch orderings on rough paper.

Using a deductive skills test in selection

A deductive skills test earns its place when a job analysis shows that people must apply rules exactly. It is less useful on its own for roles that depend mainly on spotting patterns in data, where an inductive reasoning test may be a better match, or on weighing up business arguments, where a critical reasoning test fits.

Scores are best read in bands from Very Low to Very High, combined with evidence from interviews, work samples and references. Avoid treating any score as a pass or fail. You can see how the deductive reasoning test sits within our wider aptitude tests range.

Frequently asked questions

What is the difference between deductive and inductive reasoning?

Deduction works out what must follow from given statements. Induction works out a likely rule from examples. A deductive conclusion is certain if the premises are true; an inductive one is a best inference.

What does Cannot tell mean in a deductive reasoning question?

It means the statements do not give enough information to decide whether the conclusion is true or false. It is a correct answer in its own right, not a guess.

Should I use my own knowledge to answer?

No. Use only the information given, even when it differs from real life. Bringing in outside knowledge is one of the most common causes of errors.

How can I prepare for a deductive skills test?

Practise with logic puzzles, check you understand each response option, and get into the habit of looking for a counterexample before you commit to an answer.

References

1. Johnson-Laird, P. N. (2010). Mental models and human reasoning. Proceedings of the National Academy of Sciences, 107(43), 18243–18250.
2. Wason, P. C. (1968). Reasoning about a rule. Quarterly Journal of Experimental Psychology, 20(3), 273–281.
3. Stanovich, K. E. & West, R. F. (2002). Individual differences in reasoning: implications for the rationality debate? In T. Gilovich, D. Griffin & D. Kahneman (Eds.), Heuristics and Biases: The Psychology of Intuitive Judgment (pp. 421–440). Cambridge University Press.