6.1 Types of Reasoning: Verbal, Non-Verbal, Deductive, Inductive & Analogical

Types of Reasoning: Verbal, Non-Verbal, Deductive, Inductive & Analogical

Quick Answer: Types of reasoning is the first bullet of Unit 5 and the map for everything that follows. Two independent taxonomies operate simultaneously. By presentation format, items are verbal (language- or number-coded) or non-verbal / figural (diagram-coded). By inferential direction, reasoning is deductive (general to particular, appraised as valid / invalid and sound / unsound), inductive (particular to general, appraised as strong / weak and cogent / uncogent), abductive (observations to best explanation), or analogical (case to case).

Candidates routinely treat Units 5 and 6 as two unconnected question banks. The syllabus does not: it opens Unit 5 with "Types of reasoning" precisely because the same small taxonomy generates the number series in Unit 5, the syllogism in Unit 6, and the research-design items in Unit 2. Learning the taxonomy once converts scattered practice into a single diagnostic routine — identify the type, then apply that type's appraisal vocabulary.

1. Taxonomy One: Presentation Format

[!NOTE] Examination reality check. Paper 1 is bilingual and delivered as a computer-based test with no scratch-paper advantage for figural manipulation, and the NTA has consistently weighted verbal reasoning far above figural reasoning. Allocate preparation time accordingly: master the verbal archetypes in Sections 6.2 to 6.6 first, and treat non-verbal patterns as a short revision pass rather than a major investment.

Analytical reasoning is sometimes listed as a third format. It denotes multi-constraint puzzle items — seating arrangements, floor-and-flat allocation, scheduling grids — where several conditions must be reconciled simultaneously. It is verbal in stimulus but distinctive in that the solution requires building an external representation (a grid or a table) rather than extracting a single rule.

2. Taxonomy Two: Direction of Inference

A. Deductive Reasoning — Necessity

Deduction moves from accepted general premises to a conclusion that follows necessarily. If the premises are true and the form is correct, the conclusion cannot be false. Deduction is truth-preserving but not content-expanding: the conclusion unpacks information already contained in the premises.

All teachers in this institution hold a doctoral degree.   (general premise)
Dr. Rao is a teacher in this institution.                  (particular premise)
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Therefore, Dr. Rao holds a doctoral degree.                (necessary conclusion)

B. Inductive Reasoning — Probability

Induction moves from particular observations to a probable generalisation. It is content-expanding but not truth-preserving: the conclusion asserts more than the premises guarantee, so true premises can accompany a false conclusion. Every empirical generalisation in research methodology — the inference from sample to population treated in Section 3.2 — is inductive.

The first 400 sampled colleges in the state report a rising enrolment ratio.
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Therefore, colleges in this state are probably experiencing rising enrolment.

Enumerative induction generalises from observed instances; statistical induction attaches an explicit probability; causal induction infers a productive relation, classically through John Stuart Mill's methods of agreement, difference and concomitant variation.

C. Abductive Reasoning — Best Explanation

Introduced by Charles Sanders Peirce, abduction begins with a surprising observation and infers the hypothesis that would best explain it. It is the logic of medical diagnosis, fault-finding and hypothesis formation in research.

Observation:  Enrolment in this department fell sharply in a single session.
Hypothesis:   The relocation of the campus best explains the fall.
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Therefore, the relocation is probably the cause.

Abduction is appraised by explanatory power, simplicity (parsimony), scope and testability — never by validity. Its characteristic failure is affirming the consequent: treating one adequate explanation as the only possible one.

D. Analogical Reasoning — Case to Case

Analogy transfers a property from one case to another on the strength of shared relevant attributes. It is neither general-to-particular nor particular-to-general but particular-to-particular, and Unit 6 names Analogies as a bullet in its own right. Irving Copi's six criteria for appraising analogical arguments are developed in Section 7.1.

3. The Appraisal Vocabulary — The Highest-Yield Distinction

The NTA tests this table more often than any other content in the reasoning units, because candidates habitually apply deductive vocabulary to inductive arguments.

Three consequences are examined directly:

1. Validity is about form, not truth. An argument with plainly false premises can be perfectly valid; an argument with all true premises can be invalid. Validity concerns whether the conclusion would have to be true if the premises were.
2. Soundness = validity + all premises actually true. A sound argument is therefore always valid, but a valid argument need not be sound.
3. "Valid" and "invalid" are category errors when applied to an inductive argument, and "strong" and "weak" are category errors when applied to a deductive one. Options that mix the vocabularies are the standard distractor.

[!WARNING] The general-to-particular shortcut is unreliable. Many handouts define deduction as "general to particular" and induction as "particular to general." This is a useful first heuristic but not a definition: "All A are B; all B are C; therefore all A are C" is general-to-general and fully deductive. The defining criterion is the strength of the claimed inferential link — necessity for deduction, probability for induction — not the scope of the propositions.

4. Mapping Reasoning Types onto the Paper 1 Blueprint

The practical routine for any reasoning item is three steps: classify the type, apply that type's appraisal vocabulary, and only then test the options. Candidates who skip the first step import the wrong standard and select a distractor that is correct under a different type.