SAT — data that support or undercut a hypothesis

Many SAT Reading and Writing questions in the Information and Ideas domain are built on a short account of research: who studied what, how the data were collected, and what the researchers hypothesize or conclude. When a graph comes with the passage, the question can no longer be answered by reading the graph alone. The data have to be read against the hypothesis: what would the researchers expect to see if they were right, and do the numbers show it? This material trains that step, which is where the harder quantitative questions of the test sit.

The ten questions each pair a research passage with its own graph: oak seedlings with and without deer fencing under three light levels, electricity use in neighborhoods with more or less tree canopy, the pitch of bird song in quiet and noisy places, a lake town's mail before and after the railroad, sea star counts through a marine heat wave, retail jobs and distance from an interstate, three generations' use of the word y'all, a seal's heart rate during a dive, a quiet pavement tested on three kinds of vehicle, and museum visitors before and after benches arrived in one gallery but not the other. The data are hypothetical, as they may be on the test.

The questions mix the forms the skill takes: choosing the data that support a conclusion when the conclusion compares two causes or has two parts, choosing the data that weaken a hypothesis about every group, a lasting effect or an immediate recovery, choosing the finding that would, if true, most directly support or weaken a conclusion drawn from the data, and completing a statement with what the data actually show. Along the way they practice the reasoning researchers use: a comparison group that did not receive the change, the difference between a change across generations and a change with age, and why a single value never shows a trend. Each explanation shows the prediction, the numbers that test it and why each wrong choice fails.

The flashcards summarize these ideas: hypotheses and predictions, controls, two-part conclusions, and why data can refute a causal claim more easily than prove one.

Practice material written by Zestly for students preparing for the SAT; it is not produced or endorsed by the College Board.

  • Work out what a hypothesis predicts before reading the answer choices
  • Choose the data from a graph that support a conclusion comparing two causes or with two parts
  • Choose the data that weaken a hypothesis about every group, a lasting effect or an immediate recovery
  • Identify the finding that would most directly support or weaken a conclusion drawn from data
  • Use a comparison group to separate a cause from a general trend
  • Complete a statement with what the data actually show

Practice material written by Zestly, based on the Command of Evidence (Quantitative and Textual) skill of the Information and Ideas domain described in the College Board's Assessment Framework for the Digital SAT Suite (version 3.01, August 2024). All studies and data are hypothetical.

Sample question

Grouped bar graph of the percent of oak seedlings surviving after three years under three light conditions, with and without deer fencing: full sun, 82 fenced and 30 unfenced; partial shade, 78 and 28; deep shade, 70 and 25.

Forester Mei Lin planted red oak seedlings in a Pennsylvania forest under three light conditions: full sun, partial shade and deep shade. In each condition she surrounded half of the seedlings with fences that kept deer out, and after three years she counted the survivors. Lin concludes that in this forest, browsing by deer limits the survival of young oaks more than shade does. Which choice best describes data from the graph that support Lin's conclusion?

See the answer

In every light condition, fenced seedlings survived at more than twice the rate of unfenced seedlings, while survival among fenced seedlings was only 12 percentage points lower in deep shade than in full sun.

The conclusion compares two factors, so the evidence must show both: fencing changes survival hugely in every condition (82 against 30, 78 against 28, 70 against 25 percent), while moving from full sun to deep shade lowers survival of fenced seedlings by only 82 − 70 = 12 points. The comparison of fenced seedlings in full sun and deep shade, the best rate among unfenced seedlings and the comparison of full sun with partial shade all describe the effect of light alone, and say nothing about whether deer matter more.

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