5.1 Verbal Reasoning: True, False, and Cannot Tell Methodology

5.1 Verbal Reasoning: True, False, and Cannot Tell Methodology

Quick Answer: In the CRE Aptitude Test's Verbal Reasoning questions, candidates evaluate whether a given statement is True, False, or Cannot Tell based only on the accompanying short passage. A statement is True only if it is directly stated or follows inescapably by deductive entailment. A statement is False if it directly contradicts or is logically refuted by the passage. If the text does not contain sufficient facts to confirm or deny the statement—even if the assertion is undeniably accurate in the real world—the mandatory verdict is Cannot Tell. Success hinges upon enforcing the "Four Corners of the Passage" rule and scrutinizing scope qualifiers (all vs. some, guaranteed vs. probable, causation vs. correlation).

The Role of Verbal Reasoning in the Aptitude Test

The Common Recruitment Examination (CRE) Aptitude Test is a speeded, 45-minute multiple-choice paper comprising 35 items (~77.1 seconds per question). Graded on a binary Pass / Fail standard, it assesses analytical, quantitative, and logical faculties essential for degree-level civil service cadres such as Administrative Officers (AO) and Executive Officers (EOII).

Within this paper, Verbal Reasoning (English) has 6 questions. The CSB's directions state that each passage is followed by three statements, which means two short passages. You assume the passage is true and mark each statement in one of three boxes:

1. True (Box A): the statement is already made or implied in the passage, or follows logically from it.
2. False (Box B): the statement contradicts what is said or implied in the passage, or what follows logically from it.
3. Can't tell (Box C): there is insufficient information in the passage to establish whether the statement is true or false.

+--------------------------------------------------------------------------+
|                       THE THREE MUTUAL TRUTH STATES                      |
+--------------------------------------------------------------------------+
|  State        | Evidentiary Requirement in the Passage                   |
|---------------+----------------------------------------------------------|
|  True         | Textual assertion OR 100% airtight deductive proof       |
|  False        | Textual contradiction OR 100% airtight logical refutation |
|  Cannot Tell  | Information is absent, ambiguous, or only probable       |
+--------------------------------------------------------------------------+

The "Four Corners of the Passage" Doctrine

The fundamental operational principle governing Verbal Reasoning is the Four Corners Rule: your universe of factual knowledge begins and ends strictly within the four physical corners of the printed stimulus.

Civil service candidates often fail this section precisely because they are well-educated, well-read, and knowledgeable about current affairs in Hong Kong. When evaluating a statement about housing, environmental subsidies or healthcare, knowledgeable candidates reflexively consult their real-world memory. If the statement matches actual policy, they instinctively mark it "True".

The Official Sample: Who Says It Matters

The CSB's sample passage reads:

Researchers have successfully mapped the genetic code of the mouse and have generously elected to make their findings available to scientists everywhere. A genetic model of the mouse is of benefit to researchers because it is believed that one hundred million years ago, both mice and humans shared a common rodent-like ancestor. This makes mice ideal substitutes for humans in genetic studies. Therefore, the mouse is one of the most useful animals for studying cancer and other diseases.

• Statement: The research findings show that humans and mice once had a common ancestor. Answer: False. The research finding is the mapped genetic code. The common ancestor is described as something it is believed, a general belief, not a finding of this research. The statement attributes the claim to the wrong source.
• Statement: It is likely that these findings, due to a similar shared genetic code, will result in research that will lead to the eradication of cancer. Answer: Can't tell. The passage says mice are useful for studying cancer, but says nothing about how successful such research will be.

The first statement is the important lesson. A statement can repeat words from the passage and still be False if it changes who made a claim, or how certain the claim is.

Scope Modifiers and Quantifier Traps

Statements in this format are typically built by manipulating scope modifiers, quantifiers, and modal verbs. Subtle lexical shifts alter the truth value of a statement from "True" to "Cannot Tell" or "False".

1. Absolute vs. Qualified Quantifiers

• Universal / Absolute Quantifiers: all, every, each, always, never, none, solely, exclusively, invariably.
• Particular / Qualified Quantifiers: some, many, several, most, often, frequently, generally, certain, at least one.

The Rule of Downward Entailment:

• If the passage establishes a Universal Affirmative ("All public rental housing estates in Kowloon are equipped with automated refuse compactors"), then a statement asserting a Particular Affirmative ("Some public rental housing estates in Kowloon are equipped with automated refuse compactors") is strictly True.
• Conversely, if the passage establishes only a Particular Affirmative ("Many public rental housing estates in Kowloon are equipped with automated refuse compactors"), a statement asserting a Universal Affirmative ("All public rental housing estates in Kowloon are equipped with automated refuse compactors") cannot be deduced. If the text does not rule out the remainder, the answer is Cannot Tell; if the text says "only some", the answer is False.

2. Modality: Possibility vs. Certainty

Pay meticulous attention to modal auxiliaries that distinguish mere potential from absolute certainty:

• Definite / Necessary: will, must, is guaranteed to, proves, confirms, invariably yields.
• Probabilistic / Contingent: may, might, could, can, is likely to, tends to, has the potential to.

If a stimulus states: "Implementing smart water metering can reduce unbilled municipal water loss by up to 14%," a test statement asserting: "The deployment of smart water meters will invariably eliminate municipal water loss" commits two lethal errors (modal inflation from can to will invariably, and scope inflation from up to 14% to eliminate). The statement is demonstrably False or Cannot Tell depending on the specific phrasing.

3. Causation vs. Correlation

Administrative prose frequently reports empirical surveys or statistical associations. A frequent trap is confusing correlation with causation.

• Correlation / Co-occurrence: "Departmental records indicate that staff units with higher flexible working participation rates exhibited lower rates of sick leave absenteeism."
• Causal Leap (The Trap): "Permitting staff to participate in flexible working schemes causes a direct reduction in the incidence of viral illnesses."

Unless the passage explicitly identifies a causal mechanism or explicitly attributes causation, you cannot infer that Factor A caused Factor B simply because they occurred together or varied in tandem. The correct response to unverified causal assertions is Cannot Tell.

4. Temporal Sequence vs. Causation (Post Hoc Ergo Propter Hoc)

Merely because Event Y occurred after Policy X does not prove Policy X produced Event Y. If the text states: "Following the introduction of the digital permit application portal in June, quarterly cross-boundary freight volume rose by 8%," an exam statement asserting: "The launch of the digital portal generated the 8% growth in freight traffic" is Cannot Tell unless the passage states that the portal was the direct cause of the increase.

5. Negative Assertions and Double Negatives

Administrative circulars frequently employ negative constructions or restrictive prefixes (ineligible, non-compliance, unauthorized, unless). Deconstruct double negatives methodically:

• "It is not uncommon for regulatory inspections to reveal uncertified fire dampers" $\equiv$ "Inspections fairly frequently reveal uncertified fire dampers."
• "No applicant shall be approved unless they have completed statutory vetting" $\equiv$ "Statutory vetting is a mandatory prerequisite for approval."

Comprehensive Worked Example: Municipal Waste Policy (Fictional Practice Passage)

The following passage is invented for practice; the city, figures and review are fictional.

Stimulus Passage: Municipal Waste Reduction and Resource Recovery

A city's environmental authority published an interim review of its municipal solid waste (MSW) reduction trials. According to the report, public rental housing estates participating in the pilot scheme with smart food waste recycling bins recorded an average 18% reduction in domestic organic refuse disposed at landfills over a six-month monitoring period. The authority noted that resident participation rates correlated positively with the proximity of smart bins to residential block lobbies. However, the trial revealed that during peak evening hours, bin capacity bottlenecks frequently occurred in high-density estates with more than 3,000 households per block, leading to occasional localized overflow. The review emphasized that expanding smart recycling infrastructure to private residential estates requires negotiating maintenance and electricity subsidies with property management companies, as current statutory subventions apply exclusively to public rental housing. Furthermore, the report stated that mandatory waste separation will not be introduced in the commercial and industrial sector until automated collection logistics and optical sorting facilities achieve full operational readiness.

Statement 1 Evaluation

Statement 1: "During the six-month monitoring period, at least some public rental housing estates experienced smart bin capacity shortages during peak evening hours."

• Step 1: Locate Anchor Text: The third sentence states: "However, the trial revealed that during peak evening hours, bin capacity bottlenecks frequently occurred in high-density estates with more than 3,000 households per block, leading to occasional localized overflow."
• Step 2: Check Definitions and Entailment: The trial was conducted in public rental housing estates (Sentence 2). High-density estates with >3,000 households are part of this cohort. If bottlenecks frequently occurred in estates with >3,000 households, it is mathematically inescapable that at least some public rental housing estates experienced capacity shortages.
• Step 3: Evaluate Modifiers: The statement uses the qualified quantifier "at least some", which is fully substantiated by the text's "frequently occurred in high-density estates".
• Verdict: TRUE.

Statement 2 Evaluation

Statement 2: "Private residential estates in the city currently receive statutory financial subventions from the authority to cover the electricity costs of smart recycling bins."

• Step 1: Locate Anchor Text: Sentence 4 states: "The review emphasized that expanding smart recycling infrastructure to private residential estates requires negotiating maintenance and electricity subsidies with property management companies, as current statutory subventions apply exclusively to public rental housing."
• Step 2: Check for Direct Contradiction: The text explicitly notes that "current statutory subventions apply exclusively to public rental housing."
• Step 3: Logical Entailment: The word "exclusively" means restricted solely to that group to the exclusion of all others. If subventions apply exclusively to public housing, private estates by definition do not currently receive them.
• Step 4: Assess Statement: The statement asserts that private estates currently receive these statutory subsidies, which directly contradicts the word exclusively.
• Verdict: FALSE.

Statement 3 Evaluation

Statement 3: "Mandatory waste separation in commercial and industrial establishments will increase aggregate operating expenditures for retail enterprises across the city."

• Step 1: Locate Anchor Text: Sentence 5 states: "Furthermore, the report stated that mandatory waste separation will not be introduced in the commercial and industrial sector until automated collection logistics and optical sorting facilities achieve full operational readiness."
• Step 2: Check Statement Scope against Text: Does the passage mention operating expenditures, financial overhead, profit margins, or retail business balance sheets? It does not.
• Step 3: Detect the Outside Knowledge Trap: A candidate with a business or economics background might reasonably argue: "Of course mandatory waste separation increases operating expenses—companies must purchase sorting receptacles, hire sorting contractors, and pay disposal surcharges!"
• Step 4: Apply the Four Corners Rule: The passage is completely silent on commercial financial expenditures. No matter how economically plausible or realistic the assertion is in actual corporate operations, the text provides zero evidence to prove or disprove it.
• Verdict: CANNOT TELL.

+--------------------------------------------------------------------------+
|                       WORKED EXAMPLE SUMMARY TABLE                       |
+--------------------------------------------------------------------------+
| Statement    | Core Evaluative Mechanism            | Verdict            |
|--------------+--------------------------------------+--------------------|
| Statement 1  | Downward entailment ('frequently' -> | TRUE               |
|              | 'at least some')                     |                    |
| Statement 2  | Direct factual clash with            | FALSE              |
|              | 'exclusively'                        |                    |
| Statement 3  | Plausible economic claim absent from | CANNOT TELL        |
|              | the four corners of the text         |                    |
+--------------------------------------------------------------------------+

The Anatomy of Distractors in Verbal Reasoning

When reviewing questions, recognize four statement patterns that this format lends itself to:

1. The Extreme Extrapolation Distractor: Enlarges a modest claim into an all-encompassing mandate. If the text says "automated sorting reduces glass contamination", the distractor asserts "automated sorting completely eliminates all municipal waste contamination" (renders a statement False or Cannot Tell).
2. The Inverted Causality Distractor: Reverses the direction of an arrow of influence. If "low turnover rates promoted staff familiarity with departmental databases", the distractor asserts "database familiarity caused lower turnover rates".
3. The Plausible Reality Distractor: Introduces well-known public policies or common-sense observations that are completely omitted from the passage text. Candidates who fail to maintain strict text-bound discipline invariably fall into this trap by marking Cannot Tell statements as True.
4. The Partial Negation Distractor: Contradicts a single minor clause while preserving the major nouns of the passage, attempting to mislead candidates who merely match keywords rather than parsing propositional logic.

Independent Preparation Advisory

This guide is published independently by OpenExamPrep for examination preparation and self-study purposes. It is not affiliated with, authorized by, sponsored by, or endorsed by the Civil Service Bureau of the HKSAR Government or the Civil Service Examinations Unit. Candidates should consult the official CSB examination portal for administrative announcements and test schedules.