RST.11-12.2: Simpler Words, Same Science
Also written as CCSS.ELA-LITERACY.RST.11-12.2 · Cluster: Key Ideas and Details.
The Official Wording
Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms.
Common Core State Standards, Grades 11-12, Reading: Science & Technical Subjects · Read it at the source · Checked October 14, 2026
What RST.11-12.2 Means in Plain English
Juniors and seniors find what a scientific or technical text concludes, then explain its hardest process in plainer words without bending the science. An engineering handbook page on why lithium-ion batteries fade asks students to turn “solid electrolyte interphase” into everyday language and stay accurate.
Ninth and tenth grade (RST.9-10.2) traced a complex process and summarized it accurately. Grades 11-12 add translation: the summary must be simpler than the source and still correct. This is the last band of the line, the reading students need to be ready for college and careers.
RST.11-12.2 I Can Statements
- I can state a scientific text’s central conclusion in one sentence.
- I can replace technical terms with plain words that stay accurate.
- I can check my paraphrase against the text for anything lost.
RST.11-12.2 Worked Example
The handbook page is written for this page. Both answers simplify it, and only the strong one keeps every cause and condition intact.
Every lithium-ion cell begins losing capacity on its first charge. During that charge, a small share of the lithium reacts with the liquid electrolyte at the surface of the negative electrode and forms a thin film called the solid electrolyte interphase, or SEI.The film is necessary: once formed, it lets lithium ions pass while blocking further reaction between the electrolyte and the electrode. But every lithium atom locked in the film is one that can no longer carry charge, and the film keeps thickening slowly as the cell is used, especially when it is stored hot or held at full charge.Fast charging adds a second mechanism. When ions arrive faster than the electrode can absorb them, particularly in cold weather, metallic lithium deposits on the electrode surface instead of entering it. This plating takes still more lithium out of use and can grow needle-like dendrites that pierce the separator and short the cell.Capacity ratings therefore hold only under stated conditions. A cell rated to keep 80 percent of its capacity after 1,000 cycles at 25 °C may reach that point far sooner in a hot car, or on a fast charger in winter.
Common Mistakes with RST.11-12.2
Simplifying until it is wrong
“The battery wears out like a tire tread.”
Try this: Have a partner check each plain-word swap against the original sentence and flag any that change what actually happens.
Copying the jargon and calling it a summary
“The SEI forms at the negative electrode and causes capacity fade.”
Try this: Ban the text’s three hardest terms from the summary, so students must explain each one in words a ninth grader would follow.
Paraphrasing the process but missing the conclusion
A step-by-step retelling of film growth and plating that never says why capacity ratings depend on conditions
Try this: Ask students to write the text’s conclusion in one sentence before they paraphrase any process, then check the paraphrase leads to it.
Where RST.11-12.2 Fits
Practice RST.11-12.2
Quick Check
- Why does the passage call the film “necessary” if it costs capacity?
- Which conditions speed up capacity loss, according to the passage?
- Why is “wears out like a tire” not an accurate paraphrase?