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Common Core LiteracyGrades 11–12Science & Technical

RST.11-12.6: Purpose and the Questions Left Open

Also written as CCSS.ELA-LITERACY.RST.11-12.6 · Cluster: Craft and Structure.

All 29 Grades 11–12 Literacy Standards

The Official Wording

Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text, identifying important issues that remain unresolved.

Common Core State Standards, Grades 11-12, Reading: Science & Technical Subjects · Read it at the source · Checked October 14, 2026

What RST.11-12.6 Means in Plain English

Juniors and seniors work out why a scientist explains a result, describes a procedure or reports an experiment, and name the important questions the text leaves open. A review of the Hubble tension describes two ways to measure cosmic expansion so readers can see where an error might hide.

Ninth and tenth grade (RST.9-10.6) analyzed purpose by defining the question an author sets out to address. Grades 11-12 also ask what remains unanswered when the text ends. This is the last band of the line, the reading of open science that college and career readiness calls for.

RST.11-12.6 I Can Statements

  • I can explain why an author describes a method in detail.
  • I can quote where an author states the purpose of a passage.
  • I can name the important questions a science text leaves open.

RST.11-12.6 Worked Example

The review is invented for this page, though the two measurements and the disagreement between them are real. The weak answer settles for “to inform.”

Read the Story
The universe is expanding, and its present rate, the Hubble constant, can be measured two independent ways. The first works outward from nearby stars: Cepheid variables, whose pulsing reveals their true brightness and so their distance, calibrate the supernovae used to measure farther galaxies, and this distance ladder gives about 73 kilometers per second per megaparsec.The second works forward from the early universe: maps of the cosmic microwave background, light released about 380,000 years after the Big Bang, are run through the standard model of cosmology to predict today’s rate, about 67.Each method’s uncertainty is now only a percent or two, far smaller than the gap between them, so the difference can no longer be dismissed as noise. It has a name: the Hubble tension.We describe both methods step by step, not to declare a winner but so that readers can see where an error could hide. Either one method carries a mistake no one has found, or the standard model is missing something about how the universe has evolved, and the measurements now planned are designed to tell those possibilities apart.
A short passage written for this page.
Question: Why does the author describe both measurement methods in detail, and what important issues does the passage leave unresolved?
Not Yet“The author’s purpose is to inform readers about the Hubble constant. The passage explains that the universe is expanding and that scientists measured it as 73 and 67. The unresolved issue is which number is right.”“To inform” is true of almost any science text, so it says nothing about this one. It misses the stated reason for the detail, showing where an error could hide, and shrinks the open question to picking a number, when the author says the standard model itself may be incomplete.
Meets the Standard“The author describes both methods ‘not to declare a winner but so that readers can see where an error could hide.’ The detail is the point: each method is a chain of steps, Cepheids calibrating supernovae on one side and early-universe light run through the standard model on the other, and a flaw could sit at any link. Two issues remain open. First, whether one method carries an undetected error, and if so at which link. Second, if both are right, what the standard model is missing about how the universe has evolved. The author also leaves unsettled how the planned measurements will decide between those possibilities, saying only that they are designed to.”It quotes the author’s own statement of purpose, explains how the step-by-step description serves it, and names each unresolved issue precisely instead of reducing them to which number wins.
Question Stems to Use
Why does the author explain this method in so much detail?Where does the author say what the passage is for, and what it is not for?What question is still open at the end? Is there more than one?What evidence would settle each open question?How would the passage change if the author were declaring a winner?

Common Mistakes with RST.11-12.6

Calling every purpose “to inform”

“The author’s purpose is to inform readers about the expanding universe.”

Try this: Require a purpose that could only fit this text, built from what the author chooses to describe in detail and says it is for.

Shrinking the open question

“The unresolved issue is whether the answer is 67 or 73.”

Try this: Ask students to list every possibility the author leaves open, then say what new evidence would rule each one in or out.

Treating unresolved as unreliable

“Scientists don’t agree, so we can’t trust either measurement.”

Try this: Point out the reported uncertainties, and have students explain why a careful disagreement is a finding, not a failure, in the author’s account.

Where RST.11-12.6 Fits

Comes BeforeRST.9-10.6Analyze an author’s purpose by defining the question the author seeks to address.
AlongsideRI.11-12.6Determine an author’s point of view or purpose where style and content work together.RH.11-12.3Weigh explanations against the evidence and acknowledge where a text leaves matters uncertain.
Comes NextRST.11-12.8Evaluate the hypotheses, data and conclusions of a study, testing them against other sources.

Practice RST.11-12.6

Quick Check

  1. What two methods does the passage describe, and what value does each give?
  2. Why does the author explain both methods in detail?
  3. What possibilities does the author leave unresolved?

RST.11-12.6: Other Names

RST.11-12.6CCSS.ELA-LITERACY.RST.11-12.6

Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. Official wording from the Common Core State Standards PDFs at corestandards.org, last checked October 14, 2026. The explanation, I can statements, example, mistakes and practice on this page are EMStudio’s own, written beside the official wording. They are not part of the standard.