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Biostatistics & Research · single question

In research, what is MORE desirable about a confidence interval (CI)?

  1. A wider CI provides more information
  2. A narrower CI provides more precision and is preferable
  3. The CI should always include zero to be valid
  4. A 90% CI is always preferred over a 95% CI
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Correct answer: B. A narrower CI provides more precision and is preferable

A narrower confidence interval indicates greater precision in the estimate — the true value is estimated within a tighter range. Narrower CIs result from larger sample sizes. A wider CI indicates more uncertainty. For a 95% CI: if it does NOT include 0 (for differences) or 1.0 (for ratios), the result is statistically significant at p<0.05. Narrower AND not crossing the null value = most desirable.

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