Question

If a biochemical test gives the same reading for a sample on repeated testing, it is inferred that the measurement is:

• A. Precise.
• B. Accurate.
• C. Specific.
• D. Sensitive.

Hint:

Same reading every time on the same sample is about repeatability, which is precision, not accuracy.

Answer 1

The Correct Option is A

This question checks whether you can tell apart precision, accuracy, specificity, and sensitivity, four terms that are often confused in laboratory medicine.

1. Precise: Precision is about repeatability, if you test the same sample again and again and keep getting the same number, the test is precise. This is exactly the situation described in the question, so this is the answer.
2. Accurate: Accuracy is about closeness to the true value, not about repeatability. A test could repeat the same wrong number every time, that would be precise but not accurate. The question gives no information about a true value to compare against, so accuracy cannot be the answer here.
3. Specific: Specificity is a screening test property, it tells us how well the test correctly rules out people who do not have the disease. It has nothing to do with getting the same reading twice on one sample.
4. Sensitive: Sensitivity is also a screening test property, it tells us how well the test correctly picks up people who do have the disease. Again, this has nothing to do with repeat readings on a single sample.

Getting the same reading on repeated testing of the same sample is the textbook definition of precision, so option (A) is correct.

Let's summarize:

• Precision = repeatability of a result on the same sample.
• Accuracy = closeness of a result to the true value.
• Sensitivity and specificity apply to how well a test classifies diseased versus healthy people, not to repeat readings.

So the correct term for a test that gives the same reading every time is precise.