Text Structure in a Science Article
Students read a two-page article about how a city reduced traffic accidents. The first section describes the problem: busy intersections, poor lighting, 310 crashes in one year. The second section explains a cause-and-effect chain-brighter lights led drivers to see pedestrians sooner, which shortened reaction distance. The third section lists three changes the city made and the result of each. The final section compares the city's results to a neighboring city that made no changes. A student says the article is "just a list of facts" and "has no structure." Another student says the structure is "problem and solution" throughout. The teacher wants the class to identify the different structures used in different sections and explain why the author organized it that way.
1. Identify the structure of each section and explain why the author might switch structures within one article.
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The sections use different structures on purpose. Section one is description or problem framing-it establishes the situation and stakes with the 310-crash figure. Section two is cause and effect: brighter lights cause earlier detection, which causes shorter reaction distance. Section three is problem-and-solution or a sequence of changes with outcomes, pairing each action with its result. Section four is comparison, setting the changed city against an unchanged one. The author switches because each structure does a different job: framing makes the reader care, cause-and-effect explains why a fix should work, the list of changes shows what was done, and comparison supplies evidence that the changes mattered. A strong answer notes that the overall article leans problem-and-solution, but calling it that "throughout" flattens the middle sections. Recognizing the switches shows how the author builds an argument-motivate, explain, act, prove-rather than merely stacking facts.
2. How does the final comparison section strengthen the article, and what would be lost if it were removed?
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The comparison section strengthens the article by providing a control: a neighboring city with no changes gives the reader something to measure the first city against. Without it, the drop in crashes could be explained by anything-weather, population shifts, better cars. With it, the author can argue that the changes, not outside factors, likely drove the improvement. If the section were removed, the article would still explain the problem and the fixes, but it would lose its proof. The reader would be left trusting the author's word that the changes worked. A strong answer connects this to structure: the comparison is placed last because it functions as evidence that clinches the earlier explanation. It also notes a limitation-one comparison city is not a full experiment-so the section strengthens the case without proving it completely.