Is Tom's data or the internet data more reliable? Give a reason for your answer.
How to approach this question
1. Understand the concept of reliability in data: it relates to the trustworthiness and verifiability of the data source and collection method.
2. Evaluate Tom's data: We know the population (his school), the sample size, and the method (questionnaire). It is primary data.
3. Evaluate the internet data: The question explicitly states "it has no source".
4. Compare the two. Data with a known methodology is more reliable than data from an unknown, unsourced origin.
5. State which is more reliable and give the key reason (lack of source for the internet data).
Full Answer
Reliability refers to the trustworthiness of data. Tom collected his own data (primary data), so he knows the sampling method, the exact questions asked, and the population it came from. The internet data is secondary data, and the question specifically states it "has no source". Without a source, we cannot know who collected it, when it was collected, what the sample size was, or what the exact methodology was. Therefore, we cannot verify its accuracy or check for bias. Data from a known, transparent process is always more reliable than data from an unknown, anonymous source.
Common mistakes
✗ Choosing the internet data. While it has a larger scope, its lack of a source makes it fundamentally unreliable.
✗ Giving a reason that relates to comparability (e.g., "Tom's data is better because it's about Year 11s") rather than reliability.
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