Both levels of control exceed two standard deviations in the same direction on the same run. What type of error does this most likely represent?
1Random error
2Clerical error
3No error, this is within acceptable limits
4Systematic error✓ 정답
해설
Two control levels shifted in the same direction indicate a single underlying cause rather than chance, which points to systematic error such as a reagent or calibration problem. Random error would not shift both levels consistently in one direction.