Rachel · Command of Evidence

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Knowledge Foundation

Use these excerpts to see the concepts before meeting these two textual question types. A topic names the subject; a claim says something specific about it; evidence gives a reason to accept or challenge that claim.

Scientific passage · Water on Mars

Although it’s clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient water reflects a prolonged phase of warm, wet conditions—the so-called wet and warm scenario—or a brief period of melting in an otherwise consistently frozen environment. Researchers Benjamin T. Cardenas and Michael P. Lamb recently added to this debate by using data from NASA and the Mars Orbiter Laser Altimeter to map the topography of what is now a large basin in Mars’s northern hemisphere. Cardenas and Lamb concluded that the wet and warm scenario is likely correct.

Literary passage · Treasure Island

The following text is adapted from Robert Louis Stevenson’s 1883 novel Treasure Island. Bill is a sailor staying at the Admiral Benbow, an inn run by the narrator’s parents.

Every day when [Bill] came back from his stroll he would ask if any seafaring men had gone by along the road. At first we thought it was the want of company of his own kind that made him ask this question, but at last we began to see he was desirous to avoid them. When a seaman did [stay] at the Admiral Benbow (as now and then some did) he would look in at him through the curtained door before he entered the parlour; and he was always sure to be as silent as a mouse when any such was present.

Connect the concepts

Concept	Meaning	Locate it in the excerpts
Topic vs. claim	Subject area vs. a specific assertion.	Water on Mars vs. a prolonged warm, wet phase.
Background vs. conclusion	Context or procedure vs. the statement being argued.	Mapping the basin vs. “the wet and warm scenario is likely correct.”
Relevant vs. decisive	A detail must address the exact claim, not just its subject.	Asking about sailors fits either motive. Looking in through the door and staying quiet support avoidance.
Support vs. proof	Evidence increases credibility without establishing certainty.	“Likely correct” remains qualified. A supporting finding need not prove every part of the Mars explanation.
Literal meaning vs. interpretation	What the words describe vs. what that description implies.	“As silent as a mouse” describes quiet behavior; in context, that behavior supports avoidance.
One part vs. the whole claim	Preserve all required features, relationships and limits.	Bill avoids other sailors, not necessarily everyone; Mars’s prolonged conditions contrast with brief melting.
Observation vs. explanation	A detail or finding vs. an account of what it means.	Bill asks about sailors and stays quiet around them: observed behavior. The narrator first attributes this to wanting company, then recognizes avoidance.

These categories can overlap. “Conclusion” describes a claim’s role. “Relevant” describes a relationship between evidence and a particular claim, not a permanent label attached to a sentence.

Reading a dense claim

Although it’s clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient water reflects a prolonged phase of warm, wet conditions—the so-called wet and warm scenario—or a brief period of melting in an otherwise consistently frozen environment.

Cardenas and Lamb concluded that the wet and warm scenario is likely correct.

Worked example 1 · Moderate

1 · Textual illustration

Show the exact feature or pattern described in a claim.

Ghosts of the Old Year

“Ghosts of the Old Year” is an early 1900s poem by James Weldon Johnson. In the poem, the speaker describes experiencing an ongoing cycle of anticipation followed by regretful reflection: ______

Which quotation from “Ghosts of the Old Year” most effectively illustrates the claim?

“What does this brazen tongue declare, / That falling on the midnight air / Brings to my heart a sense of care / Akin to fright?”
“The snow has ceased its fluttering flight, / The wind sunk to a whisper light, / An ominous stillness fills the night, / A pause—a hush.”
“It tells of many a squandered day, / Of slighted gems and treasured clay, / Of precious stores not laid away, / Of fields unreaped.”
“And so the years go swiftly by, / Each, coming, brings ambitions high, / And each, departing, leaves a sigh / Linked to the past.”

Method

Claim-to-Quotation Map

Interpret images through their words and context. A mood alone does not establish a recurring pattern.

Literalize the claimThe speaker repeatedly looks forward with hope and later looks back with regret.
Split the requirementsKeep all three: anticipation → regretful reflection → recurrence.
Map exact wordsIn D: “coming” and “ambitions high” show anticipation; “departing” and “a sigh / Linked to the past” show later regret; “years” and “each” make the sequence recur.
Check complete fitD covers the whole pattern. C expresses regret but lacks the earlier anticipation and the repeating sequence.

Answer: D

Option	Why it fits or fails
A	A frightening midnight sound produces concern; the two-stage recurring pattern is missing.
B	Ominous stillness creates suspense or anticipation in a particular moment; later regret and recurrence are absent.
C	Wasted days and missed opportunities express regret, but do not show anticipation followed by regret in a recurring sequence.
D	Coming ambitions, departing sigh and repeated years jointly cover every part of the claim.

Closest trap: C is the closest trap. Strong evidence for one part of a claim is insufficient when the claim requires a sequence and repetition.

Takeaway: Match every feature of an abstract claim, including sequence and repetition.

Worked example 2 · Moderate

2 · Textual support

Choose a finding that makes a claim more credible.

Water on Mars

Although it’s clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient water reflects a prolonged phase of warm, wet conditions—the so-called wet and warm scenario—or a brief period of melting in an otherwise consistently frozen environment. Researchers Benjamin T. Cardenas and Michael P. Lamb recently added to this debate by using data from NASA and the Mars Orbiter Laser Altimeter to map the topography of what is now a large basin in Mars’s northern hemisphere. Cardenas and Lamb concluded that the wet and warm scenario is likely correct.

Which finding about the basin, if true, would most directly support Cardenas and Lamb’s conclusion?

Its dimensions and shape indicate that it is unlikely to have formed as the result of an asteroid or comet impact.
It has features suggesting that it once held an ocean that underwent gradual sea-level changes over an extended time.
Its physical characteristics are most consistent with it having formed as a result of a massive but short-lived influx of liquid water.
It is surrounded by channels that could have been formed either by running water or by flowing lava.

Method

Support Prediction

Support raises credibility; it does not have to prove the entire theory. Under “if true,” accept the finding and judge its logical relevance.

State the disputed variableBoth explanations allow water on Mars. They differ in duration: prolonged warm, wet conditions versus brief melting.
Compress without losing scope“The wet and warm scenario is likely correct” → “Mars likely had prolonged warm, wet conditions.” Keep likely and prolonged.
Predict supportLook for evidence requiring water to persist over an extended period.
Match the findingB describes gradual sea-level changes over an extended time. C describes a massive but short-lived influx: amount matches the topic; duration opposes the claim.

Answer: B

Option	Why it fits or fails
A	Basin origin is a different issue. Excluding an impact does not establish how long water lasted.
B	Gradual change over an extended time matches the disputed duration.
C	Massive describes amount; short-lived describes duration and favors the competing account.
D	Water or lava is ambiguous, and neither alternative establishes a prolonged wet phase.

Closest trap: C is the closest trap: it mentions liquid water but reverses the decisive duration.

Takeaway: Find the variable that separates the explanations, then predict evidence about that variable.