Choosing between three sources on screen time
You are planning a Year 6 persuasive-writing unit on the question 'Should children's screen time be limited?' You have collected three sources for students to evaluate. Source A is a 2023 blog post titled 'Screens are stealing childhood' on the website of a company that sells parental-control software. It says 'a major study proved that screen time damages children's brains' but gives no citation or link. Source B is a 2019 peer-reviewed article in a child-development journal reporting a study of 412 children; it found a small association between evening screen use and sleep delay, and it lists limitations including reliance on parent-reported data. Source C is a 2015 school newsletter reminding families about a 'no screens before bed' routine. You want students to choose sources thoughtfully rather than simply picking the most recent or the most dramatic.
1. Rank the three sources for reliability if the purpose is to make a claim about the effects of screen time, and explain your reasoning with reference to specific features of each.
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Source B is the most reliable for this purpose. It is peer-reviewed, reports a sample size and a specific finding, and states its limitations, which is a mark of careful reporting rather than marketing. Source C sits in the middle, but only for a limited use. It has no commercial interest driving its message, but it is a brief school reminder from 2015, not research, and it offers a routine rather than evidence about effects. Source A is the least reliable for a claim about effects. The publisher sells parental-control software, so it has a financial interest in emphasising harm; it cites 'a major study' without naming or linking it; and 'proved' overstates what research can do. The ranking depends on purpose: for advertising analysis, Source A would be an excellent primary text, which is a different question.
2. A student says Source A must be true because it is the newest and uses the word 'proved'. How would you respond, and what one thing should the student check first?
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I would separate the two reasons. Recency is not the same as reliability: a 2023 blog can repeat an old or distorted claim, while a 2019 peer-reviewed study may still be the best evidence available. 'Proved' is also a warning sign rather than a guarantee. Scientific work usually reports associations, probabilities and limitations; 'proved' suggests a certainty the research rarely claims, and the phrase 'damages children's brains' is much stronger than what most studies can show. The first thing to check is the missing citation: which study, published where, with what sample? If the student cannot find it, the claim is unsupported. I would also ask them to notice the website's purpose, since it sells software, without telling them to dismiss the source entirely.
3. Explain why Source C might still be useful in the unit even though it is not research.
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Source C is useful for a different job. It is a real example of a school trying to persuade families to change a routine, so students can analyse its audience, purpose and tone, and compare how a school newsletter makes a case compared with a commercial blog. It also shows how advice circulates in a community, which is relevant context for the debate. The key teaching point is matching the source to the purpose: Source C cannot establish whether screen time affects sleep, but it can show what one school chose to recommend and how it framed that recommendation. Students can also note its limits, such as its age and lack of evidence, which reinforces the difference between a claim and evidence for a claim.