MA State Trooper cheat sheet

Deductive validity: if the premises are true and the form is valid, the conclusion must be true; validity concerns form, not factual truth.

Contrapositive is always equivalent to the original conditional: "if P then Q" equals "if not Q then not P"; the converse ("if Q then P") is not equivalent.

Necessary vs sufficient: a necessary condition must hold for the outcome; a sufficient condition guarantees it. "Only if" marks a necessary condition; "if" marks a sufficient one.

Syllogism check: an undistributed middle term or an illicit major/minor term invalidates the argument; test by substituting concrete categories.

Weaken/strengthen questions: the correct answer changes the likelihood of the conclusion while staying inside the stated scope; answers about unrelated issues are irrelevant.

Assumption questions: negate the candidate answer; if negation destroys the argument, the statement is a required assumption.

Ordering and scheduling puzzles: draw a linear or grid diagram, place the most constrained item first, and propagate fixed positions before testing alternatives.

Correlation is not causation; alternative explanations include reverse causation, common cause, and selection bias.

Main idea = the claim the whole passage supports; supporting details answer who, what, when, where, or how much, and are wrong answers when the stem asks for the main point.

Inference must be forced by the text: if a reader needs outside knowledge or a guess, the choice is unsupported.

Tone and purpose words (advocate, criticize, describe, compare) are signaled by evaluative adjectives, concession clauses, and the final sentence.

"EXCEPT" and "NOT" stems: evaluate each choice against the passage and eliminate the three that the passage supports.

Active-voice incident report order: date/time, location, persons involved, observed facts, actions taken, disposition; keep first person and past tense.

Objectivity rule: report observable behavior ("smelled of alcohol, slurred speech") rather than conclusions ("was drunk").

Chronological and causal connectors (therefore, however, nevertheless, subsequently) carry the author's logic; misreading them flips meaning.

Plain-language revision: one idea per sentence, subject and verb near the front, replace nominalizations ("made a determination") with verbs ("determined").

Priority ranking in police scenarios: immediate threat to life first, then securing the scene and preserving evidence, then documentation and notification.

Use of force decision sequence: presence and verbal commands, then de-escalation and time/distance/cover, then the lowest reasonable force option proportional to the threat.

Escalation of force ends when the threat ends; reassess and render aid once the subject is controlled.

Supervisor notification is required for any force beyond un-resisted handcuffing, any injury, any firearm discharge, or any in-custody death, per typical policy.

Integrity rule: a minor violation by a colleague is addressed directly or reported up the chain; covering up converts a minor issue into a serious one.

Bias check: decisions must rest on specific observed behavior and articulable facts, not on demeanor, dress, race, or neighborhood.

Conflict de-escalation: acknowledge the person's concern, state the lawful reason for the action, offer the available choices, and give a clear consequence for noncompliance.

Confidential information is shared on a need-to-know basis only; media and public inquiries route to the designated public information officer.

Speed = distance / time; to convert mph to feet per second, multiply by 1.4667 (60 mph = 88 ft/s).

Reaction distance = speed (ft/s) x reaction time (s); total stopping distance = reaction distance + braking distance.

Percentage change = (new - old) / old x 100; a 20% increase followed by a 20% decrease yields a net 4% decrease, not zero.

Rate problems: set up unit cancellation so unwanted units divide out (miles/hour x hours = miles).

Averages: total = mean x count; to find a missing value, subtract the known sum from the required total.

Ratio scaling: keep both parts in the same units before simplifying, and scale both terms by the same factor.

Table and chart reading: check axis labels, units, and whether the baseline starts at zero before comparing bar heights.

Probability of independent events multiplies; probability of either of two mutually exclusive events adds.

Encoding strategy: convert a scene into categories (persons, vehicles, objects, environment) and rehearse each category once.

Person description order: sex, race, age range, height, weight/build, hair, eyes, facial hair, clothing top to bottom, scars/tattoos, then direction of travel.

Vehicle recall sequence: license plate (state and characters), color, year range, body style, make/model, distinguishing damage or stickers.

Chunking improves short-term retention: group a plate as 3-3 or 2-3-2 and a phone number as 3-3-4.

Weapon and hands check: observe the hands and waistband first; hands are the primary threat indicator in any contact.

Spatial rotation: track a single landmark through the rotation and verify handedness (left/right swap) rather than rotating the whole image mentally.

Map and diagram questions: fix north, then convert "left/right" to compass directions before answering.

Eyewitness confidence is a weak predictor of accuracy; description quality depends on viewing conditions, duration, stress, and weapon focus.

Deductive validity: if the premises are true and the form is valid, the conclusion must be true; validity concerns form, not factual truth.

Contrapositive is always equivalent to the original conditional: "if P then Q" equals "if not Q then not P"; the converse ("if Q then P") is not equivalent.

Necessary vs sufficient: a necessary condition must hold for the outcome; a sufficient condition guarantees it. "Only if" marks a necessary condition; "if" marks a sufficient one.

Syllogism check: an undistributed middle term or an illicit major/minor term invalidates the argument; test by substituting concrete categories.

Weaken/strengthen questions: the correct answer changes the likelihood of the conclusion while staying inside the stated scope; answers about unrelated issues are irrelevant.

Assumption questions: negate the candidate answer; if negation destroys the argument, the statement is a required assumption.

Ordering and scheduling puzzles: draw a linear or grid diagram, place the most constrained item first, and propagate fixed positions before testing alternatives.

Correlation is not causation; alternative explanations include reverse causation, common cause, and selection bias.