GSET key terms

A stated fact or claim offered as support for a conclusion in an argument. Premises are the reasons given; they are what the arguer expects you to accept before the conclusion follows.

The claim an argument is trying to establish, usually signalled by words such as therefore, thus, or hence. Identifying it correctly is the first step in evaluating any reasoning passage.

An unstated belief the argument requires in order to work. If the assumption is false, the conclusion loses support, which is why assumption questions ask for what must be true.

A conclusion drawn from evidence rather than stated outright. On the exam you are often asked which statement is best supported, meaning which inference the passage licenses without going beyond the given information.

A structure in which the conclusion follows necessarily from the premises: if the premises are true, the conclusion cannot be false. Validity concerns form, not the actual truth of the premises.

A valid argument whose premises are all actually true. Soundness adds factual correctness to logical form, so a sound argument guarantees a true conclusion.

Something that must hold for a claim to be true, though it may not be enough on its own. In conditional language it appears on the right of 'only if' and is required but not sufficient.

A circumstance whose presence guarantees the outcome. It is enough by itself, whereas a necessary condition is merely required. Confusing the two is a common source of wrong answer choices.

A specific case that shows a general claim or rule to be false. Offering one is the standard way to weaken an argument that generalises from limited evidence.

To reduce the support an argument's evidence gives its conclusion, usually by introducing an alternative explanation or a gap in the reasoning. Weakening does not require proving the conclusion false.

To make an argument's conclusion more likely by supplying additional support, ruling out an objection, or confirming a hidden assumption. The best answer adds real force rather than restating the premise.

A statistical association in which two variables tend to move together. Correlation alone never establishes causation, and treating it as proof of cause is a frequently tested flaw.

A relationship in which one factor actually produces a change in another. Establishing it requires ruling out coincidence, reverse direction, and third variables that could explain the association.

An unmeasured factor that influences both the supposed cause and the observed effect, creating a misleading association. Its presence undermines causal claims drawn from observational data.

A distortion that arises when the group studied is not representative of the population being described. Conclusions generalised from a skewed sample are unreliable regardless of sample size.

A subset that mirrors the relevant characteristics of the larger population, often achieved through random selection. Only from such a sample can results be safely extended to the whole group.

A broad claim extended from particular observations to a wider class. It is legitimate only when the observed cases are numerous and typical of the group being described.

The arithmetic average, found by summing all values and dividing by the count. It is sensitive to extreme values, so a few outliers can pull it far from the typical data point.

The middle value when data are arranged in order, or the average of the two middle values for an even count. Unlike the mean, it resists distortion by outliers.

The value that occurs most frequently in a data set. A set may have no mode or several, and the mode is the only average usable for non-numeric categories.

A measure of how far values typically spread from the mean. A small value indicates tightly clustered data; a large one indicates wide dispersion around the average.

The position of a value relative to the rest of a distribution, expressed as the percentage of observations falling at or below it. The 90th percentile exceeds ninety per cent of the data.

A comparison of two quantities expressing how many times one contains the other. Ratios can be scaled up or down without changing their meaning, which makes them useful for proportional reasoning.

A statement that two ratios are equal, allowing an unknown quantity to be found by cross-multiplication. Many word problems about scaling and mixtures reduce to setting up a proportion.

The difference between a new and an original value, divided by the original and expressed as a percentage. The denominator is always the starting figure, not the final one.

An average in which each value contributes in proportion to its assigned weight rather than equally. It is essential when combining groups of different sizes or differing importance.

A quantity measured against another, such as distance per unit time or cost per item. Rate problems are usually solved by arranging the relationship so unwanted units cancel.

A whole number, positive, negative, or zero, without a fractional part. Properties such as oddness, evenness, and divisibility apply only to integers and are frequently tested.

An integer greater than one whose only positive divisors are one and itself. Two is the only even prime, and one is not prime by definition.

An integer that divides another exactly, leaving no remainder. Listing factors in pairs helps find the greatest common factor and simplifies fractions efficiently.

The product of a given integer and any other integer. The least common multiple of two numbers is the smallest value both divide into evenly.

The central point a passage develops as a whole, broader than any single sentence. Correct answers to main-idea questions cover the entire text rather than one supporting detail.

A specific fact, example, or reason used to develop or defend the main idea. Detail questions ask what the passage states explicitly, so the answer must be traceable to the text.

The author's attitude toward the subject, conveyed through word choice and emphasis. It may be critical, neutral, cautious, or approving, and answer choices often differ by subtle degree.

The use of matching grammatical forms for items in a list or comparison. Faulty parallelism is a common error tested in sentence correction and improves clarity when fixed.

A word, phrase, or clause that describes another element in the sentence. A modifier is misplaced or dangling when the element it describes is absent or unclear.

The rule that a verb must match its subject in number and person. Interrupting phrases and inverted word order often disguise the true subject and cause errors.

A single sentence stating the central claim an essay will defend. A strong thesis is specific, arguable, and previews the line of reasoning developed in the body.

The sentence that introduces the focus of a body paragraph and links it to the thesis. It guides the reader through the argument and prevents paragraphs from drifting off point.

An opposing view that a writer acknowledges and then answers. Addressing it strengthens credibility by showing the argument has been tested rather than asserted one-sidedly.

The quality of writing in which ideas connect logically and flow smoothly from sentence to sentence. Transitional words and consistent terminology are the main tools for achieving it.