Information and Ideas

Recognizing the Question Type

Question type	What you are being asked to do
Central idea	Summarize the passage’s main claim or development
Detail	Locate and accurately paraphrase stated information
Inference	Take one small, supported step beyond what is stated
Textual evidence	Find information that directly supports a claim
Quantitative evidence	Match a claim to values or trends in a graph or table

Overall Strategies

When dealing with information and ideas problems, the passage will most likely (especially for module 2) throw in a bunch of jargon and unnecessary details to complicate the paragraph. The main goal before answering the question is simplifying the passage without losing any critical information. The similar process can be applied to the answer choices too!

Problem-solving strategy

If a passage mentions a species (e.g. Tyrannosaurus Rex), always replace it with something simpler, like “species A.”
Rephrase jargony sentences to make it simpler/understandable. For example, “The researchers posit that the phenomenon is attributable to a confluence of environmental and genetic factors” can be simplified to “Researchers think the phenomenon is caused by both environmental and genetic factors.”
Circle the main subject and underline the main verb in each sentence. Ignore long names, dates, parenthetical definitions, and examples until you understand who did what.
Mark logic words such as however, because, although, therefore, and for example. Replace them mentally with simple labels such as contrast, cause, concession, result, and example.
Assign short labels to groups and variables. For example, turn “participants exposed to the multisensory intervention” into “Group A” and “phonemic discrimination accuracy” into “accuracy.”
After each sentence, add its job to a short mental outline: old idea, new evidence, result, or conclusion. Do not try to memorize every detail.
Summarize the entire passage in one plain sentence before evaluating the choices. Return to exact names or numbers only when a choice requires them.

Central Ideas and Details

Central-idea questions ask what the passage is mostly trying to communicate. A correct answer should:

cover most or all of the passage,
include the central conclusion,
avoid unnecessary details,
match the passage’s level of certainty.

A useful test is to complete the sentence, “The passage mainly explains that ___.” If an answer summarizes only one example, it is probably too narrow.

Many passages follow a simple structure: background, a turn, and a conclusion. Words such as but, however, although, and recently often signal the turn. The main idea frequently comes after that turn because the author is moving from an older view to the point the passage wants to emphasize.

Example. Bioacousticians once assumed that anthropogenic noise uniformly impairs avian signaling because low-frequency traffic sounds mask birds’ vocalizations. Recent spectrographic analyses, however, indicate that some urban populations exhibit upward frequency shifts, producing higher-pitched calls that remain distinguishable within the same acoustic environment. Which choice best states the central idea of the text?

A. Urban noise prevents most bird populations from communicating with one another.
B. Some birds have adapted their songs in ways that help them communicate despite urban noise.
C. Low-frequency sounds are easier for birds to produce than high-frequency sounds are.
D. Scientists no longer believe that urban noise affects animal communication.

B is correct because it captures the passage’s main development: some birds counter low-frequency traffic noise by shifting their calls upward. The technical terms do not change the simple structure: old belief—noise disrupts calls; new evidence—some birds adjust. A and D contradict that finding, while C introduces a comparison the text does not make.

Example. Ecologists have often treated the bright throat patches of male rivermouth fish as signals that evolved primarily through female mate choice. Yet females in several populations cannot distinguish the patches under the turbid conditions in which courtship usually occurs. Males, by contrast, display the patches during territorial confrontations near the water’s clearer surface, and rivals respond more cautiously to males with brighter patches. These findings do not rule out a role for mate choice, but they indicate that competition among males may have contributed substantially to the patches’ evolution. Which choice best states the main idea of the text?

A. Female rivermouth fish probably prefer bright throat patches even though the patches are difficult to see during courtship.
B. Evidence about where the patches are visible and how rival males respond suggests that male competition, not only mate choice, may have shaped the patches.
C. Turbid water has caused rivermouth fish to move courtship displays closer to the surface.
D. Bright throat patches evolved exclusively as signals used during territorial confrontations between males.

B is correct because it captures the conventional explanation, the contrasting evidence, and the qualified conclusion that male competition also mattered. A asserts a preference the text does not establish. C invents a behavioral change, and D ignores the passage’s caution that mate choice may still have played a role.

For a detail question, locate the relevant sentence and paraphrase it. Match what the passage states rather than adding an inference.

Preserve:

who did what,
cause and effect,
the direction of a comparison,
the passage’s degree of certainty.

Inferences

An inference is one small logical step from the information in the passage, not a new theory.

Choose an answer supported by the passage without relying on prior knowledge of technical terms. Also check whether a choice confuses correlation with causation: correlation does NOT mean causation!

Example. Museum researchers investigated whether interpretive-label density affects visitor engagement with an abstract painting. Visitors randomly received either a concise label or a label containing additional curatorial context. The concise-label group demonstrated longer visual dwell time, but delayed-recall scores for factual information did not differ between the groups. Which conclusion is best supported?

A. Shorter labels cause visitors to enjoy paintings more.
B. Visitors who read longer labels remember fewer facts about paintings.
C. The shorter label was associated with longer viewing time but not with better factual recall.
D. Label length has no relationship to how visitors respond to paintings.

C is correct because visual dwell time simply means viewing time and delayed-recall scores measure remembered facts; the choice states both results without claiming that the label caused enjoyment. A relies on enjoyment, which was not measured; B contradicts the equal recall result; and D ignores the difference in viewing time.

Example. British-American linguist Bobington K. Smithsonian compared two groups of adults learning an unfamiliar sound contrast. Both groups completed the same routine listening exercises, but one group also saw an animation showing lingua (tongue) position. Immediately after training, the animation group distinguished the sounds more accurately than the other group. One month later, the groups performed equally on the original sounds, but the animation group was more accurate on new words spoken by unfamiliar speakers. Which conclusion is best supported?

A. Viewing tongue position prevented the animation group’s accuracy from declining during the month after training.
B. The animation improved immediate performance and may have helped learners apply the sound contrast to unfamiliar speech a month later.
C. Listening exercises alone are ineffective for learning sound contrasts that do not occur in a learner’s language.
D. The animation group would accurately distinguish any unfamiliar sound contrast after one month.

B is correct because it reflects both measured advantages while cautiously describing the later transfer to new words and speakers. A is unsupported because the groups became equal on the original sounds, and the study does not establish each group’s amount of decline. C contradicts the non-animation group’s successful performance on the original sounds. D generalizes far beyond the single contrast tested.

Command of Evidence

For textual-evidence questions, break the claim into components and ask what quotation would directly prove each component.

If a claim says a species adapted because its habitat became drier, strong evidence should show:

that the habitat became drier,
that the species changed,
ideally, a connection between those facts.

Evidence showing only that the species lives in a dry place is related, but insufficient.

The strongest evidence does more than mention the same topic. It connects to the exact relationship in the claim. If the claim contains two parts, check that the evidence supports both.

Example. A researcher hypothesizes that the waxy coating on the leaves of the coastal shrub M. littoralis helps the plant tolerate the brackish conditions of the Mediterranean basin by limiting the entry of salt through the pores on leaf surfaces, rather than by reducing water loss. Which finding, if true, would most directly support the hypothesis?

A. Coated leaves and leaves whose coating was removed lost water at similar rates in salt-free air, but the leaves without the coating accumulated more salt when sprayed with saltwater.
B. Plants with thicker coatings tended to grow closer to the shoreline than plants with thinner coatings did.
C. Removing the coating caused leaves to lose more water and accumulate more salt when sprayed with saltwater.
D. The roots of M. littoralis accumulated less salt than the roots of a related inland species did.

A is correct because it isolates the proposed mechanism: removing the coating changes salt accumulation without changing water loss. B is correlational and does not identify what the coating does. C supports both possible explanations, so it cannot distinguish the salt-entry hypothesis from the water-loss alternative. D concerns roots rather than salt entering through leaf surfaces. Note that brackish means salty.

Graphs and Tables

Before reading the answer choices, record:

the axes,
the units,
the groups being compared,
the overall trend,
any important numerical difference.

Then translate each answer into a numerical claim and check it against the visual.

Do not begin by interpreting what the data might mean. First determine what the graph literally shows. A choice that gives an interesting explanation is still wrong if it is not backed up by the data. Eliminate all of the answers not backed up by the data and then choose the correct answer based on the hypothesis/claim provided.

An increase from 20% to 30% is an increase of 10 percentage points, but also a 50% relative increase. These descriptions are not interchangeable.

Example. A table reports mean germination rates for untreated seeds and seeds subjected to thermal scarification, a heat treatment intended to weaken the seed coat, from two plant populations.

Population	Untreated	Heat-treated
Ridge	42%	63%
Valley	58%	61%

A student claims that heat treatment increased germination in both populations but had a much larger effect on Ridge seeds. Which choice most effectively uses data from the table to support the claim?

A. Germination was 63% for heat-treated Ridge seeds and 61% for heat-treated Valley seeds.
B. Heat treatment increased germination by 21 percentage points for Ridge seeds, compared with 3 percentage points for Valley seeds.
C. Untreated Valley seeds germinated at a rate 16 percentage points higher than untreated Ridge seeds.
D. Heat-treated Ridge seeds germinated at a rate approximately 3% higher than heat-treated Valley seeds.

B is correct because it compares the within-population changes: $63-42=21$ percentage points for Ridge and $61-58=3$ percentage points for Valley. A and D compare the treated groups with each other, not the effect of treatment within each population. C compares untreated groups and does not show that treatment increased germination.