Question

Random error associated with sampling and randomization are effectively addressed by confidence and hypothesis tests. These methods fail to address systematic errors. Systematic errors come in which of the following forms?
LIST:
A. Confounding bias
B. Information bias
C. Selection bias
D. Direction bias
E. Random bias

• A. A, C and D only
• B. A, B and C only
• C. A, C and E only
• D. B, C and E only

Hint:

Bias = systematic error. Random error decreases with larger samples, but bias requires careful study design.

Answer 1

The Correct Option is B

Step 1: Distinction between random and systematic errors.
- Random errors: Caused by chance fluctuations, reduced by larger sample size or statistical tests.
- Systematic errors (bias): Persistent, non-random errors due to flaws in design, data collection, or analysis.
Step 2: Systematic error types.
- Confounding bias: Occurs when a third variable distorts the association between exposure and outcome.
- Information bias: Caused by misclassification or errors in measurement of variables.
- Selection bias: Occurs when the method of selecting participants produces a sample not representative of the target population.
Step 3: Eliminating incorrect terms.
- Direction bias: Not a standard recognized form.
- Random bias: Contradictory term, since bias is systematic, not random.
Step 4: Conclusion.
Systematic errors include confounding bias, information bias, and selection bias.