Write an argument and an explanation with thesis statements, accurate credible sources, precise domain-specific language and language suited to the audience

Learning goal: This lesson teaches Ohio's 2026 standards W.8.1 and W.8.2, first implemented in 2027-28. You will write argumentative pieces and informative/explanatory pieces on the same topic, school composting, and learn every element the standards list for each. The argument includes a clear thesis statement within the introduction; an introduction of claims with clearly organized reasons and an acknowledgement of alternate or opposing claims; clear reasons and relevant evidence that are well organized, include logical reasoning and demonstrate an understanding of the topic; words, phrases and clauses that create cohesion; precise language and domain-specific vocabulary; language appropriate to the audience and purpose; accurate, credible sources; and a concluding statement or section that supports the argument. The explanation includes a clear thesis statement previewing what is to follow; relevant facts, definitions, concrete details, quotations and examples organized into broad categories; an organized text structure; appropriate and varied transitions; precise, domain-specific language suited to audience and purpose; formatting, graphics and multimedia if needed; accurate, credible sources; and a concluding section that supports the explanation.

Two purposes, one topic. An argumentative piece tries to convince a reader to accept a claim that reasonable people could dispute: "Our school should start a composting program." An informative/explanatory piece helps a reader understand something without asking them to take a side: "How composting turns cafeteria scraps into compost that enriches soil." Much of the research is shared. What differs is the thesis and how the evidence is used.

Background you need (true in general, and checkable in any credible guide). Composting is the breakdown of food scraps, leaves and other organic matter by microorganisms such as bacteria and fungi, helped by larger organisms such as worms. A working pile needs carbon-rich "browns" (dry leaves, shredded paper), nitrogen-rich "greens" (fruit and vegetable scraps, grass clippings), moisture and oxygen, which is why piles are turned or aerated. An active pile heats up as microorganisms work. Simple school and home piles usually exclude meat and dairy, which attract pests and cause odors.

Argument: thesis within the introduction (W.8.1a). The thesis states your position clearly and appears in the introduction, usually after one or two sentences of context. A clear thesis is specific and arguable: "Ridgeview Middle School should compost its fruit and vegetable scraps with a student-run program, because it would cut cafeteria trash, supply the school garden and teach science by doing it." A vague thesis ("Composting is good") is arguable but too broad to guide a focused argument: it names no action, audience or reasons.

Introduce claims, organize reasons, acknowledge opposing claims (W.8.1b). After the thesis, the introduction previews the claims in the order you will develop them. Organize reasons so each gets its own section. Then acknowledge an alternate or opposing claim fairly, in its strongest form ("Some staff worry a compost bin will smell and attract pests, and that no one will have time to run it"), before answering it. Acknowledging is not surrendering: it shows the reader you understand the whole topic.

Clear reasons, relevant evidence and logical reasoning (W.8.1c). A reason is why the claim should be accepted; evidence is the fact, data or quotation that supports the reason; reasoning is the explanation of how the evidence proves the reason. Evidence is relevant only when it bears on that reason. Logical reasoning avoids leaps: a count of scraps shows how much could be composted, not that the program will succeed.

Cohesion (W.8.1d). Words, phrases and clauses such as because, as a result, admittedly, even so, this evidence shows that and for the same reason create cohesion: they tie claim, reasons and evidence together so the reader sees how each connects.

Precise language and domain-specific vocabulary (W.8.1e and W.8.2e). Precise language names exactly what you mean: "fruit and vegetable scraps," not "stuff"; "25 kilograms a week," not "a lot." Domain-specific vocabulary is the technical language of the subject: decomposition, microorganisms, aeration, carbon-to-nitrogen balance, finished compost. Use it correctly and define it when your audience may not know it.

Language appropriate to the audience and purpose (W.8.1f and W.8.2f). The same facts are written differently for the principal and the parent-teacher group, who need costs, responsibilities and risks in a formal, respectful register, than for sixth graders joining a compost team, who need plain definitions and steps. Purpose matters too: persuading a decision-maker calls for measured confidence; explaining calls for neutral, clear description. Sarcasm, or slang as vague as "the trash situation is gross," undercuts both.

Accurate, credible sources (W.8.1g and W.8.2h). A credible source has a knowledgeable, identifiable author or organization, explains where its information comes from, and has no strong reason to mislead. An accurate source's claims check out against other credible sources. A university extension service or government environmental agency guide is usually credible; a compost-bin advertisement promising "finished compost in 7 days!" is not, because it is selling a product and its claim does not match what other guides say (most describe weeks to months). Name your sources in the text.

Concluding statement or section (W.8.1h and W.8.2i). The conclusion supports what came before: it restates the thesis in light of the evidence, draws out a consequence and, for an argument, may call for a specific action. It adds no new, unsupported claim.

Explanation: thesis previewing what follows (W.8.2a). "Composting turns scraps into compost, a dark material that enriches soil, through three conditions, the right ingredients, air and water, and time, and each can be managed in a school bin." The reader now knows the sections to come.

Facts, definitions, details, quotations and examples in broad categories (W.8.2b). Group information into broad categories that become sections: ingredients, conditions, timeline. Under each, use relevant facts, definitions, concrete details, a short quotation from a credible guide and examples.

Organized text structure (W.8.2c). Choose the structure that fits each part: description (what finished compost looks like), chronology/sequence (the stages over weeks), problem/solution (odor and its fix), compare/contrast (browns versus greens) and cause/effect (too wet causes a smell). An explanation can combine them, section by section.

Appropriate and varied transitions (W.8.2d). Vary transitions to fit the relationship: sequence (first, after about two weeks), contrast (by contrast, however), cause (as a result, because), example (for instance). Repeating also and then hides relationships instead of showing them.

Formatting, graphics and multimedia if needed (W.8.2g). Headings for each category, a table comparing browns and greens, a diagram of the stages and, in a digital version, a short video of turning a pile can clarify information. "If needed" is a test, not an invitation: ask what the reader would find harder to see without the feature. A table earns its place when two things must be compared item by item; a heading earns it when a reader needs to find a section; a video earns it when a motion is hard to describe in words. A picture that only decorates fails the test and is left out.

Common misconception. Students often think acknowledging the other side weakens an argument. It strengthens it, provided you answer the opposing claim with evidence. Leaving out the obvious objection makes readers suspect you have no answer.

Worked example 1 — Model argument (excerpt), addressed to the principal and parent-teacher group. Introduction: "Each week Ridgeview's cafeteria throws away food that could feed a garden. According to a waste audit our science class conducted in October (invented figures for this lesson), the cafeteria discards about 40 kilograms of food a week, about 25 kilograms of it fruit and vegetable scraps. Ridgeview should compost those scraps through a student-run program, because it would reduce trash, supply the school garden with compost and teach decomposition through practice." Opposing claim: "Admittedly, staff have raised a fair concern: a bin could smell and attract pests. Even so, the county extension office's composting guide (a model source) states that odors usually come from too much moisture or from meat and dairy; our plan excludes both and uses a closed, aerated bin." Reason and evidence: "Because 25 kilograms of scraps a week would otherwise go to the dumpster, composting them would remove a large share of our food waste; as a result, fewer bags would leave the building." Conclusion: "Composting would turn a disposal cost into a teaching resource. We ask you to approve a one-semester trial with a student team." Check: thesis in the introduction; claims previewed in order; opposing claim acknowledged and answered; cohesive transitions (admittedly, even so, because, as a result); precise figures; formal register for decision-makers; a named credible source; a conclusion that supports rather than adds.

Worked example 2 — Model explanation (excerpt), for sixth graders joining the team. Thesis: "Compost forms when three things are managed: the right mix of ingredients, air and water, and time." Heading 1, Ingredients (compare/contrast): "Greens are nitrogen-rich, like apple cores. Browns are carbon-rich, like dry leaves. By contrast with greens, browns are dry and slow to break down; a pile needs both." Heading 2, Air and water (cause/effect): "Microorganisms need oxygen, so we turn the pile. If the pile is too wet, air cannot reach them, and as a result it smells." Heading 3, Time (sequence): "First, the pile warms as microorganisms work; after several weeks, it cools; eventually the material becomes dark and crumbly." Formatting and graphic, checked against "if needed": the three headings match the three conditions the thesis previews, so a sixth grader can find each one, and a two-column table lists greens and browns side by side, because that comparison is easier to read in columns than in a sentence. No picture is added for decoration. The conclusion returns to the three conditions.

Worked example 3 — Judging sources for accuracy and credibility. Source A: a university extension guide, authors named, explains its methods; says compost usually takes weeks to months. Source B: a compost-bin advertisement promising "finished compost in 7 days." Source C: an anonymous post saying "you can compost anything." A and B conflict; a second credible guide agrees with A, B gives no conditions or evidence for its 7-day figure, and B has a sales motive, so B's claim is unsupported and unreliable for this argument unless its conditions can be checked. C conflicts with credible guidance on meat and dairy and has no author. Use A; mention B only as an example of an unreliable claim.

Representation task — two plans side by side. Draw two columns, Argument and Explanation. In each, write the thesis, the claims or broad categories with their evidence, the text structure for each section, three varied transitions, three domain-specific terms with definitions, your audience and one register choice, your sources with a credibility note, and a one-sentence conclusion. Mark where the opposing claim is acknowledged in the argument and where a graphic belongs in the explanation.

Independent performance. Choose a school improvement you can research (composting, bike racks, a quiet reading room). Write a 600-word argument addressed to a decision-maker and a 500-word explanation of how the thing works for younger students.

Success criteria (argument): a clear thesis in the introduction; claims introduced and reasons clearly organized; an alternate or opposing claim acknowledged fairly and answered; clear reasons supported by relevant evidence and logical reasoning that shows you understand the topic; cohesive words, phrases and clauses; precise and domain-specific language; formal language suited to the audience and purpose; at least two accurate, credible sources named; a concluding section that supports the argument. Success criteria (explanation): a thesis previewing the sections; facts, definitions, concrete details, a quotation and examples organized into broad categories; at least two text structures used appropriately; appropriate and varied transitions; precise, domain-specific language defined for younger readers; a heading system and one graphic or multimedia element that clarifies; accurate, credible sources; a conclusion that supports the explanation.