Two Sources on Later Start Times: Scope, Causation, and Synthesis
A candidate is comparing two sources about later school start times. Source A is a district report: a 450-student high school moved its start time from 7:45 to 8:30 a.m.; over 18 months, average GPA rose 0.2, tardies fell 14 percent, and bus costs did not change; the parent survey had a 62 percent response rate. Source B is a newspaper op-ed arguing that the change is 'a scheduling fad.' It cites a neighboring district where GPA did not improve after a similar shift, and it claims the report ignores athletes who leave early for games. The candidate says, 'The sources contradict each other, so neither is reliable,' and plans to write that the evidence is evenly divided. The candidate also treats the 0.2 GPA gain as proof that start times caused better grades. A teacher asks for a more careful comparison before the candidate drafts a synthesis essay.
1. Are the two sources in direct contradiction? Distinguish what each source actually claims and explain why the candidate's 'evenly divided' conclusion is premature.
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They are not in direct contradiction on the same proposition. Source A reports outcomes for one 450-student high school over 18 months: GPA rose 0.2, tardies fell 14 percent, bus costs stayed the same, and the parent survey had a 62 percent response rate. Source B cites a different neighboring district where GPA did not improve and raises a scope objection about athletes.
A failure in another district does not refute a gain in Source A's district; it limits how broadly that result can be generalized. The sources conflict about generalizability, not about the same measured outcome. 'Evenly divided' is premature because the sources differ in scope, method, and completeness. The candidate should compare design and relevance before weighing them.
2. The candidate treats the 0.2 GPA gain as proof of causation. What alternative explanations should be considered, and what does the 62 percent survey response rate add?
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A before-and-after GPA gain is not proof of causation. Alternative explanations include a simultaneous grading-policy change, a new tutoring program, differences in the cohort of students, or a novelty effect during the 18 months. Without a comparison group, the report cannot isolate start time as the cause.
The 62 percent response rate matters only for survey-based claims: 38 percent did not respond, so parent opinion may be unrepresentative. But the GPA and tardy figures come from school records, not the survey, so the response rate does not undermine those numbers. The candidate should match each limitation to the specific claim it affects.
3. What evidence would help resolve the disagreement between Source A and Source B, and how should the candidate frame the op-ed's athlete objection?
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Useful evidence would include a comparison group of similar schools that did not shift start times, a longer follow-up, and outcome data from Source B's neighboring district with its sample size and grading context. The candidate should also check whether both districts measured GPA the same way.
The athlete objection is a scope and implementation concern: a later start may create conflicts with early departures for games. It does not refute academic gains; it identifies a cost or a subgroup effect. The candidate should frame it as a limitation on implementation, not as proof that the start-time change failed.