Study Notes: Analogy (SOF NSO Logical Reasoning)

Overview

Analogy is a core logical reasoning topic that tests your ability to identify relationships between pairs of items and apply the same relationship to find missing elements. In SOF NSO, analogy questions appear in three formats: word analogy, number analogy, and figural analogy. Each type follows the fundamental principle A:B :: C:D, meaning "A is related to B in the same way C is related to D."

This topic is crucial because it assesses pattern recognition, logical thinking, and the ability to establish connections—skills that underpin scientific reasoning. Expect 3–5 analogy questions in the Logical Reasoning section of NSO. Mastering analogy requires you to quickly identify the type of relationship (such as cause-effect, part-whole, or mathematical operations) and systematically apply it. Strong performance here builds confidence for the entire reasoning section and improves your overall percentile ranking.

The key to success is practice across all three types and developing a mental checklist of common relationship patterns. Unlike some reasoning topics that rely purely on visual skills, analogy uniquely combines vocabulary, mathematical thinking, and pattern recognition—making it an excellent indicator of overall logical ability.

Key Concepts

• **Basic Analogy Structure**: All analogy questions follow A:B :: C:D format. You're either given three terms and must find the fourth, or you must identify which pair shares the same relationship as a given pair.

• **Word Analogy Relationships**: Common patterns include synonyms/antonyms, category-member (animal:lion), part-whole (wheel:car), cause-effect (virus:disease), tool-function (pen:write), and degree (hot:scalding).

• **Number Analogy Patterns**: Look for arithmetic operations (addition, subtraction, multiplication, division), square/cube relationships, prime numbers, digit sums, positional values, or sequence patterns between the numbers.

• **Figural Analogy Logic**: Identify transformations like rotation, reflection, increase/decrease in elements, shading changes, position shifts, or shape conversions. The relationship applies visually rather than verbally or numerically.

• **Multiple Relationships**: Some complex analogies involve two simultaneous relationships. For example, 3:9 :: 4:16 involves both "multiply by itself" and "consecutive integers as bases."

• **Elimination Strategy**: When multiple options seem plausible, test each by clearly stating the relationship in words. The correct answer must maintain the exact same logical connection.

• **Direction Matters**: In analogies, the order is critical. "Doctor:Hospital" (person:workplace) is different from "Hospital:Doctor" (workplace:person). Always maintain the directional flow of the relationship.

• **Common Trap Patterns**: Avoid surface-level connections. Just because two words belong to the same broad category doesn't mean they share the specific relationship needed for analogy completion.

Formulas / Key Facts

**Word Analogy Relationship Types:**

• Synonym: Happy:Joyful :: Sad:Sorrowful
• Antonym: Hot:Cold :: Day:Night
• Part-to-Whole: Page:Book :: Branch:Tree
• Category-Member: Bird:Sparrow :: Flower:Rose
• Tool-Function: Scissors:Cut :: Hammer:Hit
• Cause-Effect: Rain:Flood :: Fire:Smoke
• Degree: Good:Excellent :: Bad:Terrible
• Characteristic: Ice:Cold :: Sun:Bright

**Number Analogy Patterns:**

• Square relationship: 2:4 :: 5:25 (number squared)
• Product relationship: 3:12 :: 5:20 (multiply by 4)
• Sum relationship: 2:5 :: 3:7 (add constant)
• Digit sum: 12:3 :: 23:5 (sum of digits)
• Reverse: 23:32 :: 45:54 (digits reversed)
• Prime/composite patterns: 2:4 :: 3:9 (prime to its square)

**Figural Analogy Transformations:**

• 90° or 180° rotation clockwise/anticlockwise
• Horizontal or vertical reflection (mirror image)
• Element addition or removal
• Shading inversion (black to white or vice versa)
• Size increase or decrease
• Position exchange of internal elements

Worked Examples

**Example 1 (Word Analogy):** Question: Pen:Write :: Knife:? Options: (A) Sharp (B) Cut (C) Steel (D) Kitchen

*Solution:* First, identify the relationship between Pen and Write. A pen is a tool whose function is to write. Therefore, we need a word that represents the function of a knife. A knife is a tool whose function is to cut. The answer is **(B) Cut**. Note that "Sharp" is a characteristic, not a function, and "Steel" is a material, not the purpose.

**Example 2 (Number Analogy):** Question: 3:27 :: 5:? Options: (A) 50 (B) 75 (C) 125 (D) 150

*Solution:* Examine the relationship between 3 and 27. Notice that 3³ = 27 (3 cubed equals 27). Apply the same relationship to 5: 5³ = 125. The answer is **(C) 125**. This is a cube relationship, not multiplication by 9, which would give 45.

**Example 3 (Figural Analogy):** Question: If a triangle pointing upward becomes a triangle pointing downward, then a square should become: Options: (A) Rectangle (B) Circle (C) Square rotated 180° (D) Smaller square

*Solution:* The relationship is a 180° rotation. A triangle pointing up, when rotated 180°, points down. A square rotated 180° still looks like a square in the same position because it has rotational symmetry. The answer is **(C) Square rotated 180°**, though visually unchanged, represents the same transformation applied. If the question shows actual figures with internal markings, look for those markings to shift by 180°.

Common Mistakes

**Mistake 1**: Identifying a vague category match instead of the specific relationship. For example, in "Cat:Kitten :: Dog:?", answering "Animal" instead of "Puppy." The relationship is adult:young, not member:category. **Fix**: Always verbalize the precise relationship in a sentence: "A cat's young one is called a kitten, so a dog's young one is called a puppy."

**Mistake 2**: Applying arithmetic operations in the wrong order for number analogies. Seeing 4:16 :: 6:36 and thinking "add 12" instead of recognizing the squaring pattern. **Fix**: Test multiple mathematical relationships systematically: addition, subtraction, multiplication, division, squares, cubes, and digit manipulation.

**Mistake 3**: Focusing on superficial visual similarity in figural analogies rather than the transformation rule. Choosing a figure that "looks similar" instead of one that follows the same change pattern. **Fix**: Clearly identify what changed (rotation angle, number of elements, shading) and apply that exact change to the second pair.

**Mistake 4**: Reversing the relationship direction. If given "Effect:Cause :: X:Y", providing an answer that maintains "Cause:Effect" order. **Fix**: Write out the relationship with arrows: A→B means "A leads to B" or "A is part of B." Maintain the exact directional logic.

**Mistake 5**: Overthinking simple analogies by looking for complex hidden patterns when a straightforward relationship exists. **Fix**: Start with the most obvious relationships first (opposites, categories, basic math operations) before exploring complex multi-step patterns.

Quick Reference

• Analogy format: A:B :: C:D means A relates to B as C relates to D
• Three types: Word (meaning-based), Number (mathematical), Figural (visual transformation)
• Word patterns: synonym, antonym, part-whole, tool-function, cause-effect, category-member
• Number patterns: squares, cubes, multiples, digit sum, prime relationships, arithmetic operations
• Figural changes: rotation, reflection, element count, shading, size, position
• Always state the relationship in clear words before selecting an answer