In QC results, which binary classification is commonly used?

• A. Normal / Abnormal
• B. Positive / Negative
• C. Low / High
• D. Accept / Reject

Answer: (B)

The main idea is that QC results are usually a simple yes-or-no call about the presence or absence of the target. Positive or Negative captures that dichotomy directly: a result either detects the analyte (positive) or it does not (negative). This clear binary framing makes it easy to track across runs, apply decision rules, and feed into QC tools like control charts that monitor the proportion of positives over time. It’s a universal way labs interpret results, whether you’re checking a test, a control material, or a diagnostic threshold.

Other terms describe magnitude or status rather than a straightforward pass/fail outcome. Normal/Abnormal is more clinical language, Low/High refers to the level of a measurement rather than a binary decision, and while Accept/Reject is used, it’s often about batch decisions rather than the per-result classification itself. Positive/Negative remains the most widely applicable binary classification forQC results.