Non-random sampling (Edexcel GCSE Statistics): Flashcards
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Practise the cards
9 cards from this deck
Best method for 70 dentists from 250 surgeries?
Best method for 70 dentists from 250 surgeries?
Cluster: randomly select surgeries, survey all dentists
Quota: 70% women in 40-person sample — numbers?
Quota: 70% women in 40-person sample — numbers?
28 women and 12 men
When to use judgement sampling? Give example.
When to use judgement sampling? Give example.
When expert can pick typical cases, e.g., headteacher
Give a periodicity risk in systematic sampling.
Give a periodicity risk in systematic sampling.
Interval matches a pattern (e.g., every 4th corner house)
Method when headteacher handpicks classes? State reason
Method when headteacher handpicks classes? State reason
Judgement sampling; selected by expert, risk of bias
Sample 70 dentists by visiting nearest clinics. Method?
Sample 70 dentists by visiting nearest clinics. Method?
Opportunity sampling; convenience sample, high bias risk
Need 40 people: 70% women, 30% men. Which method?
Need 40 people: 70% women, 30% men. Which method?
Quota sampling; sample 28 women and 12 men
Systematically sample 40 of 160 houses — interval?
Systematically sample 40 of 160 houses — interval?
Every 4th house (160÷40=4). Beware periodic patterns.
Systematically sample 40 houses from 160: interval?
Systematically sample 40 houses from 160: interval?
Every 4th house (160 ÷ 40 = 4); check pattern bias.