Biostatistics & Research · single question
BIAS in a research study is BEST defined as:
Show answer and explanation
Correct answer: D. Systematic error that leads to incorrect estimates of association or effect
- A. Random variation due to chance is addressed by statistical testing (p-values, confidence intervals) and is not bias.
- B. The probability a result is due to chance is the p-value — not bias.
- C. The spread of data around the mean is the standard deviation — not the definition of bias.
- D. Correct. Bias is a SYSTEMATIC (non-random) error in study design, data collection, or analysis that results in outcomes that consistently deviate from the truth. Unlike random error, bias cannot be reduced by increasing sample size.
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